The University of Southampton
Warning! Your browser is out-of-date and not compatible with this website. Please download a new secure and faster browser to view this website correctly.

Colloquia

Can't Reason or Won't Reason? Challenging students to think more deeply about concepts by building models
David Sands University of Hull                                                            7th October 2016

This colloquium will be of very general interest and undergraduates will, as always, be most welcome.

Trying to work out just what students do when faced with even simple problems is as ongoing area of research In this talk Dr Sands will demonstrate some examples of the difficulties experienced by students: inconsistent thinking, guesswork, faulty reasoning, flawed assumptions, and so on. Dr Sands' approach to this has been to put emphasis on models and modelling. Much of the elements of modelling are well known in the literature, but he will present here a theoretical basis for building models and show how the method can be used in teaching and assessment.

'A Heterogeneous III-V / Si3N4 Nanophotonic Integration Platform for Chip-Based Nonlinear and Quantum Optics
Marcelo Davanco NIST    
                                                           22nd July 2016

Current state-of-the-art integrated photonic technology allows the creation of complex circuits that incorporate a great number of functional elements. While such technology has been primarily aimed at classical communications, photonic integrated circuits have recently become very attractive for photonic quantum information, in view of their scalability, stability, and functionality. A recent trend in photonic integration has been heterogeneous integration platforms, in which different types of optical materials are combined and processed on a single substrate. This enables highly optimized devices through specific properties from the individual material types. In this talk, Dr Davanco will report on a heterogeneous photonic integration platform to produce photonic circuits, based on Si3N4 waveguides, which incorporate on-chip triggered single-photon sources based on single self-assembled InAs/GaAs quantum dots (QDs). Self-assembled InAs QDs are to date the most promising triggered solid-state single photon sources for quantum information. In counterpoint, Si3N4 waveguides offer low-loss propagation with tailorable dispersion and high Kerr nonlinearities, which can be explored for linear and nonlinear optical signal processing. This integration platform will enable a new class of highly efficient and versatile integrated nonlinear and quantum photonic devices.

Non-Equilibrium States in Quantum Rotors
Benno Meier University of Southampton       
                                                           24th June 2016

Molecules or molecular groups that may rotate freely at low temperatures display spin isomerism: the symmetry of their overall wavefunction is conserved and hence a change in symmetry of its rotational part requires a corresponding change in symmetry of its spin part. Relaxation to thermal equilibrium requires an interaction that couples the spatial and spin parts. The absence of such an interaction suppresses any relaxation, and even in dense systems non-equilibrium states may be preserved for many hours. The process of equilibration, referred to as nuclear spin conversion, is well known in nuclear magnetic resonance (NMR), but also affects bulk properties such as the specific heat. 
In his talk, Dr Meier will present nuclear magnetic resonance and dielectric studies of nuclear spin conversion in fullerene-encapsulated water, H2O@C60, and the methyl moiety of 4-methyl-pyridine. He will also describe how non-equilibrium spin isomer distributions may be generated in metabolites such as pyruvate by dynamic nuclear polarization.

Nature's Palette
Michele Thomsen Planetary Science Institute, Tucson AZ and Los Alamos NM       
                                                           3rd June 2016

Like an artist's palette, Nature has a set of common physical processes to employ to make a magnetosphere. The nature of a particular work of art depends on how much of each of the colors is used and how they are combined on the canvas, i.e., on the particular talent of the artist. In much the same way, the nature of a magnetosphere is determined by the particular properties of a given planet and how those properties influence the dynamical significance of the various processes. Dr Thomsen will examine some of the processes in Nature's palette and see how their importance varies from magnetosphere to magnetosphere within our own solar system. Comparing actual realizations of magnetospheres to which we have in-situ access enables us to see the interplay between the physical processes and the peculiar conditions of each body. As we contemplate the extra-solar planets we are now discovering, we need to consider other possible combinations of colors from this palette: What other wonderful and exotic magnetospheres might exist throughout the universe?

Imaging in Direct and Recripocal Space at the Diamond Light Source utilising I13's Unique Coherence Properties
Ulrich Wagner Diamond Light Source Ltd       
                                                           27th May 2016

I13 is a 250 m-long hard x-ray beamline (6 keV to 35 keV) at the Diamond Light Source. It comprises two fully independent and simultaneously operating experimental endstations: one for imaging in direct space, currently providing high resolution in-line phase-contrast tomography; and one for imaging in reciprocal space using coherent diffraction based techniques like Ptychography, Bragg-CDI and Photon-Correlation Spectroscopy. In addition, the particular design of this branch provides an outstandingly large lateral coherence length beyond 200um, lending itself to unique research in the field of coherent x-ray optics, the development of novel instrumentation and imaging techniques in relation to interferometry, holography and speckle tracking. 
After an overview of the Diamond Light Source and the specifics of synchrotron light, the talk will delineate advances in instrumentation achieved at Diamond, like the Double-Mini Beta Scheme and a new generation of horizontally deflecting beamline optics, entailing the design of I13 and its two endstations. These facilities and the science they support will be adumbrated by discussing some representative experiments in more detail. Eventually the talk will give a short outlook on the future development of I13 towards nano-imaging and the prospects for I13 provided by a machine upgrade towards an ultimate storage ring.

Neglected terms and hidden gems in atom-light interaction
Matthias Sonnleitner University of Glasgow       
                                                           20th May 2016

The mechanical interaction between atoms and laser light is the basis of many modern technologies and a continuous source of fascinating research. Today cold and ultracold atomic clouds can be controlled and manipulated at a level that allows atom opticians to measure the tiniest of forces and, for instance, test fundamental theories on gravity.
Given this success and precision it might be time to look at one of the usually neglected aspects of atom-light interaction, the so-called Roentgen term. In this talk, Dr Sonnleitner will introduce this largely unknown interaction and explain its physical origin. He will then present some surprising theoretical results and discuss possible implications on current experiments.

Generation of Mechanical Interference Fringes by Multi-Photon Quantum Measurement
Michael Vanner University of Oxford        
                                                           29th April 2016

Quantum optomechanics uses the radiation-pressure interaction and the tools of quantum optics to extend the control of individual quantum systems to a macroscopic regime. The field is currently receiving a surge of interest for its potential to contribute to both fundamental and applied science with current research directions including table-top tests of quantum gravity and the development of high-precision weak-force sensors. In this talk, Dr Vanner will describe some recent experimental work that observed mechanical interference fringes as a key step towards generating non-classical states of motion of a massive mechanical resonator.

Quantum Dynamics of Photo-Activated Biomolecules
Alexandra Olaya-Castro University College, London        
                                                           18th March 2016

Photosynthesis is the process by which plants, algae and some bacteria use sunlight to initiate the chemical reactions that sustain life processes. It is well known that the primary steps of the photosynthetic process rely on quantum mechanical phenomena. For instance, excitons or the collective absorbing electronic states of light-harvesting biomolecules are a clear manifestation of collective quantum behaviour of the chromophores that form these complexes. However, when it refers to the transfer and conversion of excitation energy in the picosecond time scale, it is not entirely clear which dynamical features can only be predicted within a quantum mechanical framework and how they correlate to the effective energy flow in photosynthetic complexes. In this talk, Dr Olaya-Castro will discuss research shedding light on this issue.

Hazards Under the sea - deep waters don't run still....
Mike Clare National Oceanography Centre, University of Southampton         
                                                           11th March 2016

The ocean makes up 71% of the Earth's surface, yet only 5% has been mapped in detail largely due to the challenge of working in extreme water depths featuring high pressures, zero visibility and limited or no background information. Remarkably we know more about the surface of Mars than our own planet. Despite this large unknown, demands for global energy and communication links push hydrocarbon exploration and seafloor infrastructure into deeper and unchartered waters. To develop in such areas, it necessary to cross slopes that feature a wide array of potentially damaging, but often poorly understood geohazards. In this talk, Dr Clare introduces some of these geohazards, including the largest landslides on the face of our planet that can trigger devastating tsunamis, fast flowing subsea sediment avalanches that that can transport more sediment than all the world's rivers combined, and major earthquake-faults at the contacts of continental plates. New monitoring of geohazards performed by NOC Southampton and collaborators is providing the first direct observations of marine geohazards. Mike will outline how new technology and ongoing research are allowing us to tackle the challenge.

Get a better Photon: shape, sieve, and switch
Peter Mosley University of Bath         
                                                           4th March 2016

The development of higher-performance single-photon sources is a pressing issue for photonic quantum information processing, as independent sources are currently unable to provide sufficient numbers of identical single photons simultaneously. Dr Mosley will discuss recent progress in the field of photon-pair sources based on nonlinear optics and present the latest results from the University of Bath. He will describe his group's development of a source incorporating dispersion-engineered photonic crystal fibre, novel filtering techniques, and active switching to generate high-purity heralded photons in an all-fibre architecture.

Shackleton's Endurance Expedition 1914-1916 - with Hurley's slides and as seen through the eyes of physicist R W James
Robert Hollingdale Royal Institute of Navigation         
                                                           19th February 2016

100 years ago, Sir Ernest Shackleton's Imperial Trans-Antarctic Expedition was marooned at the improvised 'Patience Camp' on the Weddel Sea ice floe. The Endurance, ice-locked a year earlier, had sunk in November, and the perilous 800 mile rescue voyage of the James Caird would begin only five months later. Shackleton's successful rescue of his entire crew turned the failure into a legend, beautifully illustrated by the glass plates, celluloid images and early film footage of the expedition photographer Frank Hurley. 
This talk, using Hurley's slides, will describe the Endurance expedition through the eyes of the expedition physicist R W James – one of four scientists amongst the 28-man crew. After serving as an artillery spotter on the Western Front, James went on to research X-ray crystallography with W L Bragg, was elected a FRS, and became VC of the University of Cape Town.

Novel Techniques for Portable Cold Atom Experiments
Graham Bruce University of St Andrews         
                                                           12th February 2016

The drive to miniaturise atom-based metrological devices is an important area in modern research. Dr Bruce will report on progress towards realising such a portable setup with three main results: a) a method of determining vacuum pressure using cold atoms, removing the need for a standard vacuum gauge, b) the creation of a portable magneto-optical trap which has been used to demonstrate cold atom physics at public events across Scotland, and c) the development of computer generated holographic techniques for the production of highly flexible and multi-wavelength optical traps with a simple apparatus. Furthermore he will demonstrate the applicability of these holographic traps for two experiments: ring traps for rotation sensing and the creation of a cold atom device that can be used as an investigation of the topological Kondo effect.

Introduction to the Physics of Chocolate
Isabella Van Damme Mars Chocolate         
                                                           29th January 2016

 For most people, chocolate is an irresistible delicious treat. Others see it as an equally irresistible dense suspension of solids in a lipid phase that lends itself to some interesting research. The formation and manipulation of this suspension is key to deliver the smooth, attractive textural attributes of chocolate. This presentation will aim to demonstrate how physics plays an important role in understanding and controlling the properties of chocolate and highlight some of the major research questions.

Thermodynamics and Information at the Nanoscale
Dr Janet Anders University of Exeter           
                                                           8th January 2016

Einstein realized that the fluctuations of a Brownian particle can be used to ascertain the properties of its environment. In the first part of the talk, Dr Anders will report on a nano-scale thermodynamic experiment with heated optically trapped nanospheres in a dilute gas. By developing a new theoretical model that captures the non-equilibrium situation of the particles, this allowed measurement of the surface temperature of the trapped spheres, and observation of temperature gradients on the nanoscale. Dr Anders will then give a brief overview of quantum thermodynamics theory and discuss the role of coherences and correlations.

The Science and Applications of National Nuclear Security
Neil Gasper AWE Aldermaston           
                                                           11th December 2015

Today the world sees growing threats from terrorism, ageing nuclear power stations and a resurgence in design and building of new nuclear power stations. Nuclear Security is evermore required and covers a number of applications from control of current material, through detection of illegally trafficked material to analysis after an incident. The science and technology in support of this is broad. This talk will look at (some of) the physics, mathematics and engineering that contributes to the Nuclear Security applications.

Relativistic Cosmology in the 21st Century
Professor Pedro Ferreira University of Oxford            
                                                           4th December 2015

Physical Cosmology is the success story of modern physics. Observations of the large scale structure of the universe have allowed us to characterize the cosmological model with unprecedented precision. What is less appreciated is that we have learnt a great deal about the building blocks of Relativistic Cosmology: about space-time, it origins and the role of general relativity in the evolution of the universe. In this talk, Prof Ferreira will show how, over the last two decades, we have made tremendous progress in characterizing the overall metric of space-time – its homogeneity and isotropy – as well as its properties at very early times. He will show how exploring general relativity can play a crucial role in solving one of the big cosmological puzzles (the dark energy problem) and how cosmology can be used to find new, precision constraints on general relativity. He will discuss a vision of the future in which we attempt to completely map out the large scale characteristics of space-time using innovative techniques and future surveys.

Electron Charge and Spin State readout in Carbon Nanotube Quantum Dots
Dr Mark Buitelaar University College, London            
                                                           27th November 2015

Dr Buitelaar will discuss electron charge and spin state readout of carbon nanotube quantum dots which are of interest for solid-state quantum information processing. The first part of the talk will focus on weakly coupled double quantum dots in which certain electron transitions between the dots are forbidden by spin conservation. This is important as it allows us to convert the electron spin degree of freedom to a much easier measurable charge state or current. The second part of the talk will focus on radio-frequency reflectometry as a tool to read out these charge states in a fast and non-invasive way. Dr Buitelaar will describe results for which this technique is combined with microwave spectroscopy to measure charge relaxation and coherence times.

Superconducting Single Photon-Detectors
Robert Hadfield University of Glasgow            
                                                           20th November 2015

Single photon detectors based on superconducting nanowires have emerged as a highly promising alternative for infrared single photon detection. These devices offer single photon sensitivity from visible to mid infrared wavelengths with high efficiency, low dark count rates and tens of picosecond timing precision. Professor Hadfield will discuss the basic device design, materials considerations, fabrication through electron beam lithography and integration with advanced optical structures. He will also discuss prospects for scale-up from microscopic single pixel devices to large area arrays, and how these low temperature devices can be mounted in practical closed-cycle systems. He will then give an overview of applications where these devices are being deployed, including long distance quantum cryptography, remote sensing, laser medicine and development of optical quantum computing.

Ultra Intense Laser Plasm Interactions: physics at the extremes
Kate Lancaster University of York            
                                                           6th November 2015

Ultra intense lasers are capable of producing some of the most extreme conditions on earth in terms of temperatures, pressures, and electric and magnetic fields. There is a wealth of science that can be uncovered during these interactions that spans from fusion energy to quantum electrodynamics. This talk will give a snap shot of the current state of play of the science possible on these large scale lasers, especially focusing on laser driven fusion energy. The talk will conclude with some predictions about the future of the field and the regimes of science we will be able to access.

Supernovae Type 1a as Distance Indicators: success and pitfalls
Roberto Trotta Imperial College, London              
                                                           30th October 2015

Supernovae type Ia (SNIa) are one of the observational pillars of the concordance cosmological model, and have been instrumental in determining the existence of dark energy. While the observational effort has been very successful in finding over 1,000 cosmologically useful SNIa's, the sophistication of statistical methods employed to analyse the data and infer cosmological parameters has been lagging behind.

In this talk, Dr Trotta will present an overview of the status of SNIa cosmology, as well as new results from BAHAMAS (BAyesian HierArchical Modeling for the Analysis of Supernova cosmology), a fully Bayesian analysis of SNIa data, a demonstrably superior approach which improves on many shortcomings of the usual method.

Mobility, Fire Power, Protection - squaring the circle of armoured vehicle design
Major Will Fowler Military historian                   
                                                           16th October 2015

September 2016 will mark the 100th anniversary of the battle of Flers Courcelette and the first use of tracked armoured vehicles in war. The tarpaulin shrouded shapes were called tanks as a cover as they were moved across France to the Somme and the name stuck. With their introduction the nature of land warfare changed forever. This talk will be a layman's look at the physics behind tank design, mobility and fire power. Few tank designs have managed to combine the three design features in one vehicle and we will look at the challenge this presents.

Understanding the Rabi model beyond the rotating-wave approximation
Dr Elinor Irish University of Southampton                     
                                                           9th October 2015

The Rabi model – a single two-level system interacting with a quantum oscillator – is one of the simplest yet also one of the most enigmatic of quantum models. Recent years have seen a resurgence of interest in the Rabi model, as the drive toward practical quantum technology has produced experiments with capabilities that push the limits of our understanding of the underlying physics. Motivated by both theoretical and experimental considerations, Dr Irish will discuss some of the progress that has been made toward understanding the Rabi model beyond the standard rotating-wave approximation, focusing on the role of unitary transformation techniques. This will not be a heavily mathematical talk, instead emphasising physical intuition and linking theory to experiments.

ICE: Atom Interferometry in Microgravity
Dr Brynle Barrett Institut d'Optique, Universite de Bordeaux                           
                                                           5th June 2015

Over the past 20 years, atom interferometers have emerged as ultra-sensitive instruments with applications in both fundamental physics and industry. Their high sensitivity to inertial effects has been utilized to measure, for instance, the gravitational acceleration g, or the rotation rate of the Earth, with unprecedented precision. However, typically atom interferometers are realized in laboratory environments with large, static setups which suffer from a variety of limitations, such as the size of the vacuum system and the corresponding maximum free-fall time of the atoms. It is thought that the full potential of atom interferometers can only be realized in Space, where the atoms are in perfect free-fall with the apparatus. In this talk, Dr Barrett will give an overview of the ICE experiment, which is the first mobile dual-species interferometer in existence. It is capable of operating onboard the Novespace A310 Zero-G aircraft during parabolic flight?the ultimate goal of which is to test the weak equivalence principle in a microgravity environment. This involves precisely measuring the relative acceleration between two atoms with different masses (87Rb and 39K). Dr Barrett will discuss the challenges involved in this work, and conclude with recent experimental results.

Experiments with Rydberg Positronium Atoms
Dr David Cassidy University College, London                           
                                                           29th May 2015

Positronium (Ps) is a metastable atomic system formed from an electron bound to a positron. The ~100 ns lifetime of these atoms does not directly impede spectroscopic investigations of Ps, but the creation of suitable positron sources certainly does. Positron traps have made it possible to produce intense pulses containing up to 107 positrons in a ns burst using weak incident positron beams. These can be used to make a "gas" of positronium which in turn can be probed with pulsed lasers in much the same way as any other atomic species. The ability to create a Ps gas makes feasible hitherto impractical (or impossible) experiments, such as the production of molecular positronium. In this talk, Dr Cassidy will discuss ongoing experiments in which highly excited atomic states of Ps can be created and studied, including Doppler-free 2-photon state-selective production of Rydberg Ps and the production of selected Stark-States in electric fields. The ultimate goal is the electrostatic manipulation of Rydberg Ps with inhomogeneous electric fields to produce Ps "atom-optics" and focus and decelerate Ps atoms, enabling many new experiments, from spectroscopy to gravity measurements.

 

Optically Actuated Micro-Robotics/Imaging without a camera
Dr Dave Phillips & Dr Matt Edgar University of Glasgow                            
                                                           22nd May 2015

 

Direct laser writing is a powerful and flexible tool with which to create 3D micro-scale structures with nanoscale features. These structures can then be dispersed in aqueous media and dynamically actuated in three dimensions using optical tweezers. The ability to build, actuate and precisely measure the motion of complex microscopic structures heralds a variety of new applications - optically actuated micro-robotics.
Dr Phillips will describe the design, fabrication of control of these devices, and the real-time 3-D stereomicroscopy of their Brownian motion. Feedback control transforms these structures into quantitative tools, for applications including surface imaging and a new form of hydrodynamic micro-manipulation.


Camera technology has undergone three significant shifts: first from manually to electro-mechanically driven hardware; then from the analogue age of photosensitive chemistry to the digital era of solid-state sensors and storage; and now to the computational age, when computer algorithms and modified hardware (including high-speed MEMS, ultrafast timing circuits, single photon detectors and high-performance computing) can enhance camera operations, overcome their limitations and revolutionize their applications. 
Dr Edgar will describe a camera that can take infrared images using a cheap photodiode in place of a costly pixelated sensor, and will cover some current investigations where such a 'single-pixel camera' could have important applications.

Flying a constellation of geostationary satellites in the dynamic space environment
Mark Dickinson Inmarsat                            
                                                           8th May 2015

 Inmarsat currently operates a constellation of 11 geostationary telecommunication satellites ranging in age from almost 20 years to only a few months. These satellites provide mobile connectivity on a global basis, typically to ships, aircraft, media, the energy sector but also for first responders as seen with the tragic recent events in Nepal. The presentation will touch on the evolution in technology and design principles used for these spacecraft which allows them to operate safely within the highly dynamic space environment. This includes continuous exposure to the galactic cosmic ray flux and also particles originating from the Sun, especially during events such as large coronal mass ejections.

Quantum Networks with Ion-Cavity Systems
Matthias Keller University of Sussex                            
                                                           1st May 2015

 Trapped ions have recently evolved to be the most successful quantum information processing systems. Several high fidelity quantum gates have been established and quantum algorithms have been implemented. Even though entanglement between up to 14 ions within the same ion trapping potential has been shown, strategies for the scaling up of the number ion qubits is still required. While complex trapping structures with several trapping zones promise an increase of up to 10s of ions, distributing quantum information processing over several nodes in a delocalised network has the potential to increase the number of qubits well beyond 100s of ions. Crucial component for these networks are interfaces between ions and photons acting as 'quantum modems'.

Dr Keller's group investigates ion-cavity systems to serve as quantum interfaces. Exploiting the interaction of ions with the mode of an optical cavity the high fidelity, bidirectional quantum state transfer between photons and ions is feasible. Furthermore, deterministic generation of entanglement between photons and ions as well as between remote ions become possible.

For tight integration of the cavities into the trapping structure and to achieve a strong interaction between ion and cavity, the Sussex group investigates optical fibre tip cavities and novel ion trap designs. In this presentation Dr Keller will give an overview of our experiments and report on the recent progress.

Quantum Cascade Lasers: from THz non-linear optics to ultra-short pulse generation
Sukhy Dhillon Laboratoire Pierre Aigrain, ENS Paris                            
                                                           20th March 2015

 

The Quantum Cascade Laser is the semiconductor solution to realise laser action over the entire mid-infrared to the terahertz (THz) regions of the electromagnetic spectrum. This wavelength agility arises from the use of intersubband transitions, transitions between confined electronic states within a set of quantum wells. The progress in this field has been rapid from high power and high temperature operation to the recent commercialization of mid-infrared QCLs for high sensitivity trace gas detection. After an overview, Dr Dhillon will present how new functionalities can be introduced using the inherent properties of QCLs. These include THz nonlinear optics by means of the high powers that approach those used in free electron lasers and short pulse generation using the ultrafast carrier dynamics of the gain recovery.

 

A Global Analysis of Erosion and Flooding due to Sea-Level Rise
Robert Nicholls University of Southampton                            
                                                           13th March 2015

Global sea-level rise has been recognised as a significant hazard for the last 25 years and there has been global-scale concern about the potential for coastal erosion and flooding. This talk will discuss the results on these issues that have been developed, with a strong emphasis on the results developed with the Dynamic Interactive Vulnerability Analysis (DIVA). This shows that both hazards could be significant, with the largest losses being due to coastal flooding. The results also show the importance of adaptation in controlling impacts – considering realistic adaptation reduces impacts dramatically. The potential role of climate mitigation will also be briefly considered.

Fundamental Physics with Antihydrogen
James Storey CERN                                 
                                                           6th March 2015

Antihydrogen, the bound state of an antiproton and a positron, was first produced at CERN in 1995 at relativistic energies. Over the past two decades tremendous progress has been made by experiments at CERN's Antiproton Decelerator (AD) facility towards the production of low energy antihydrogen that is compatible with the high precision experimental methods that have been developed for the study of hydrogen. This talk will present an overview of the current antihydrogen experiments at CERN, with particular emphasis on progress towards spectroscopy of antihydrogen with the ALPHA experiment and measuring the gravitational free-fall of antihydrogen with the AEgIS experiment.

Adventures in the Outer Solar System
Catriona Jackman University of Southampton
                                                           27th February 2015

 Dr Jackman will take you on a tour of the outer solar system, highlighting the key discoveries that have been made and the biggest questions for future exploration. Results from missions such as Galileo at Jupiter and Cassini at Saturn will highlight the diversity of planetary magnetospheric dynamics as well as the zoo of moons, some of which indicate that they can harbour life. The final portion of the talk will focus on future plans for solar system exploration. One short-term highlight is the NASA mission Juno which will arrive at Jupiter in summer 2016 and have just a year to learn as much as it can about the jovian system before its spacecraft components are fried by Jupiter's intense radiation. Other longer-term ambitions centre around the ice giants, Uranus and Neptune, which challenge our understanding of how the Sun influences planetary systems.

Probing emitter-cavity dressed states through environmental transitions
Ahsan Nazir University of Manchester
                                                           6th February 2015

 This colloquium will be of particular interest to those in the quantum/nano/photonics areas.

 The Development of Optical Lattice Clocks
Liz Bridge Durham University
                                                           9th January 2015

 Optical lattice clocks demonstrate world-leading fractional frequency uncertainty and instability. Recent publications state a fractional frequency uncertainty of 2 x 10-18 (equivalent to losing one second in 160 billion years), which is 50 times better than the caesium fountains currently used to define the unit of time. This level of certainty and stability allows us to look for temporal variations in the fundamental constants, such as the fine structure constant and the electron-proton mass ratio, and could lead to a wide range of technological advances. In this talk, Dr Bridge provide an overview of the recent progress of atomic frequency metrology, highlighting key considerations, and discuss the possible future developments, including using Rydberg spin squeezing to further reduce the instability.

 From Ghost Imaging to Quantum Tomography
Jonathan Leach Heriot-Watt University
                                                           12th December 2014

 This colloquium will be of particular interest to those in the quantum/nano/photonics areas.

How do you take images so fast that you can see light travelling through air? And how do you use the latest technology to look around corners and see objects hidden from view? Prof Leach will talk about our recent research using a very specialised camera with some very important features. The first is its sensitivity to single photons – each pixel is around ten times more sensitive than a human eye; the second is its speed – each pixel can be activated for just 67 picoseconds, that's more than a billion times faster than we can blink. The camera allows us to film at the speed of light – we can video pulses of light as they travel through air.

 

 Controlling Light at the Qunatum Level:  on-demand single-photon sources on a chip
Luca Sapienza University of Southampton                                                            28th November 2014

 The field of photonics has seen a tremendous development in recent years. The "photonic revolution", based on the use of light as the information carrier, is expected to have an impact on everyday life, providing faster and secure communication, as well as more efficient computation schemes.

 Thanks to fundamental research and technological advances, we can now generate, trap, guide and detect light at its most fundamental level, the single photon.


Dr Sapienza will give an introduction to solid-state single-photon sources and present his group's recent results on single quantum dot emitters integrated in optical cavities, on a semiconductor chip.
 

 The Shapes of the Supernovae
Justyn Maund University of Sheffield                                                            21st November 2014

 Supernovae are the violent explosions that mark the deaths of certain types of stars. The complex shapes observed for a handful of centuries-old, nearby supernovae hint at the complicated physics involved in the explosion mechanism itself. Dr Maund will provide an overview of how astronomers have attempted to observe the shapes of supernovae, and show how the technique of spectropolarimetry is our best hope for working out how some stars actually explode.

 Microscopic Mapping of III-Nitride Blue LEDs and Nanostructures
Rob Martin Univbersity of Strathclyde                                                            14th November 2014

 Quantum wells of Indium Gallium Nitride lie at the heart of the extremely efficient blue and white LEDs that are having a major impact in lighting and other commercially important areas. Prof Martin will describe work to investigate sub-micron spatial variations in these devices: both (1) naturally occurring inhomogeneities that might be expected to severely limit device performance to levels well below those currently achieved and (2) deliberately engineered nanostructures designed to improve performance (such as arrays of nanorods or core-shell LEDs). 

Superabsorption of Light via Quantum Engineering
Erik Gauger University of Oxford                                                            7th November 2014

 

Sixty years ago Robert Dicke introduced the term superradiance to describe a signature quantum effect: N atoms can collectively emit light at a rate proportional to N2. Structures that superradiate must also have enhanced absorption, but the former always dominates in natural systems. In this talk, Dr Gauger will show that modern quantum control techniques can overcome this restriction in certain simple nanostructures. The protocol for superabsorption is an instance of quantum engineering inspired by the design of naturally occurring biological systems, and opens the prospect of a new class of quantum nanotechnology with potential applications including photon detection and light harvesting.

 

The Large Synoptic Survey Telescope
Ian Shipsey University of Oxford                                                            31st October 2014

 

Technological advances have made possible the deep optical survey of a large fraction of the visible sky, enabling the search for small moving objects in the solar system, studies of the assembly history of the Milky Way, the exploration of transient sky, and the establishment of tight constraints on models of dark energy. With an 8.4 m primary mirror, and a 3.2 Gigapixel, 10 deg2 CCD camera, LSST will provide nearly an order of magnitude improvement in survey speed, and is expected in its first month of operation to survey more of the optical universe than all previous telescopes built by mankind.

 

In ten years, the LSST will survey half of the sky in six optical colors down to 27th magnitude, revealing four billion new galaxies and 10 million supernovae. LSST will produce 15 terabytes of data per night, processed by dedicated computing facilities in near real time. Prof Shipsey will discuss some of the science that will be made possible by the construction of LSST, especially dark energy science, which constitutes a profound challenge to particle physics and cosmology, and give an overview of the technical design and current status of the project.

 

The Correspondence Principle and Quantum Measurement
Mark Everitt University of Loughborough                                                            17th October 2014
An overview the quantum to classical transition for a number of systems including a simple three body problem, a two level atom coupled to a field. By considering a dissipative quantum mechanical model of the projective measurement of a qubit.
Neutrinos on Ice: using IceCube to chase a ghost particle
Jason Koskinen Niels Bohr Institute, University of Copenhagen                                                            10th October 2014
The IceCube neutrino observatory is a cubic kilometer of instrument ice situated at the South Pole.  With sensitivity to neutrinos over an energy range of 10 GeV to 10 PeV, it is a unique instrument to study both  astrophysics and fundamental partical physics.  Prof Koskinen will cover the most recent results from high-energy astrophysical neutrino detection, neutrino oscillation, and prospects for next generation upgrades.

 

 Quantum Photonics with Optical Nanofibres
Kohzo Hakuta                University of Electro-Communications, Chofu                                                                      3rd October 2014
 

Prof Hakuta will discuss quantum photonics with optical nanofibres that may open a new route to manipulate single atoms and single photons. The key idea of the method is to use sub-wavelength diameter silica fibres, termed optical nanofibres, for strongly confining the photon-mode density around the nanofibre. First, he will discuss theoretically how various freedoms of atoms and photons can be manipulated with optical nanofibres, and the experimental demonstration of how such freedoms have been manipulated with optical nanofibres. Examples include single atom spectroscopy and efficient channeling of fluorescence photons into the guided modes. Regarding the channeling, Prof Hakuta's group has shown experimentally that, by placing one "atom" on nanofibre surface, the fluorescence photons are channeled into the guided modes with efficiency higher than 20%. Furthermore, he will show theoretically that the channeling efficiency can be enhanced to 90% or higher, by fabricating cavity structure on nanofibres. Recent progress on experimental realization of nanofibre-cavity system will be discussed. Prof Hakuta will discuss also the realization of the cavity QED conditions in the Purcell regime using the nanofibre-cavity system, and report the observation of significant enhancement of the spontaneous emission rate into the nanofibre guided modes for single quantum dots. Future prospects are also discussed.

 The Rosetta Mission: the story so far
Matt Taylor                European Space Agency                                                                      23rd May 2014
 

The Rosetta Mission is the third cornerstone mission of the ESA programme Horizon 2000. The aim of the mission is to map the comet 67-P/Churyumov-Gerasimenko by remote sensing, to examine its environment insitu and its evolution in the inner solar system. The lander Philae will be the first device to land on a comet and perform in-situ science on the surface. Launched in March 2004 and after a number of gravity assists and various asteroid fly –bys, the spacecraft entered deep space hibernation in June 2011. Nearly 10 years after launch on 20th January 2014 at 10:00 UTC the spacecraft woke up from hibernation to ! get ready for comet rendez-vous. This presentation will provide a brief overview of the mission up to date and provide an insight into the exciting years we have ahead of us as Rosetta reaches and studies its target.

 Modelling Complex Self Assembly: the bad news is the good news:
Daan Frenkel                 University of Cambridge                                                                       16th May 2014

A holy grail of nano-technology is to create truly complex, multi-component structures by self assembly. In this talk, Prof Frenkel will discuss some of the most important parameters that can be used to control self-assembly: packing entropy and molecular recognition. Both the role of packing entropy and that of molecular recognition are counter-intuitive. Prof Frenkel will discuss the unexpected role of entropy as an ordering force, and will show that in molecular recognition, less is more.

Dirk Broer                   Eindhoven University of Technology                                                                       28th March 2014
Surfaces: Topographical Dynamics and Preferential Adsorption:

Liquid crystal polymer networks can be made responsive to triggers as light, temperature, moisture, pH and specific gases and chemicals. The response may manifest itself as changes in appearance such as color or transmission of light, and/or in shape when deforming from a flat film to a preset complex geometry. This presentation will focus on triggered changes in the surface topography. By manipulating local molecular order we are able to switch a surface from flat to corrugated. Protrusions may form randomly, comparable to fingerprints, or at! preset locations. When formed they change surface properties like friction and wetting. By using a similar technology, films can be made with a large internal surface area in the form of nanopores. These nanopores can selectively adsorb species depending on charge or size. The polarity of the pores can be switched by light which changes the uptake of materials.

Barry Kellett

Rutherford Appleton Library

7th February 2014 

SMART-1: Europe's First Mission to the Moon. SMART-1 was ESA's first technology demonstration mission... a small mission to test various components and technologies that ESA thought it needed for the future. For example, SMART-1 was the first ESA mission to fly Lithium batteries! However, the main technology under test was the solar electric Ion Drive. This helped SMART-1 set two new world records: the SLOWEST mission to ever reach the Moon (over 15 months!) and, second, the most fuel efficient mission to the Moon – just 80 kg of fuel used! Dr Kellett will also briefly mention Chandrayaan-1 – the 1st Indian mission to the Moon!

Kai Bongs

University of Birmingham

31st January 2014 

The iSense project brings together leading European atom interferometry groups in order to overcome the technological bottleneck in cold atom quantum technology. The field of cold atoms and precision measurements with atoms has seen 4 Nobel prizes in the last twenty years and is hosting vibrant research by 1000s of groups worldwide. However, despite groundbreaking results in quantum simulation, promising advances in quantum computing and quantum communication as well as quantum sensors surpassing the best classical devices, this field is still largely confined to the research laboratory. The reason lies in the complex and delicate laser, vacuum and electronic systems needed to create the cold atom quantum resource needed for all these applications. iSense aims at a significant shrinkage and robustness increase of the underlying technologies and to demonstrate the concept in a potable atom interferometer gravity sensor. This talk will discuss the technology and science approaches in iSense and present the current status of the project with an outlook into cold atom quantum technologies.

Suzanne Aigrain

University of Oxford

6th December 2013 

Planets orbiting other stars than the Sun were first discovered only 20 years ago, but since then their study has become one of the most active and fertile fields in astronomy. With dedicated telescopes scanning the skies continuously, we are now discovering hundreds of new systems every year, many of which are utterly unlike our own. We can also study study the atmospheres of some of these distant worlds in astonishing detail. Dr Aigrain will take us on a brief tour of recent exoplanet detection and characterisation highlights, and finish with a preview of how we might search for signs of life on another world.

Graham Taylor

University of Bath

22nd November 2013 

The dynamics of flapping flight differ fundamentally from those of fixed- or rotary-wing aircraft. This seminar will give a flavour of the Oxford research on the guidance, dynamics, and control of bird and insect flight. This research aims to uncover the fundamental organizational principles underpinning the design of naturally evolved control systems, and to apply this insight to the design of unmanned air systems. The talk will probe a few key examples, including the relationship between physics and physiology in hawkmoths, the mechanics of the insect flight motor as revealed by time-resolved X-ray tomography, and the visually-guided attack strategies of peregrine falcons.

Philippe Blondel

University of Bath

15th November 2013 

Oceans cover most of the Earth. The last decades have seen a host of wonderful discoveries, most of them using sound and sonars. This talk will present examples from around the world, taken from the presenter's own research. The first part of the talk will present the innovative sensors (many of UK design) which have revolutionised our knowledge of the "Blue Planet" and its seabeds, from mid-ocean ridges to coastal areas. The second part will focus on applications, including coastal habitats, Marine Renewable Energies and the migrations of grey whales, as well as the role of acoustic sensors in monitoring the effects of climate change and human activities as far as the Arctic.

Alexander Hein

University of Ulm

1st November 2013 

Optically Pumped Semiconductor Disk Lasers (OPSDLs) combine the unique features of high output power, excellent beam quality, and wide wavelength coverage. In the fundamental regime, the wavelengths of these sources can be continuously addressed from 0.6 Î¼m to well beyond 2.5 Î¼m by choosing an appropriate material system. The spectral band is essentially increased by generation of higher harmonics, thus, the shorter visible spectrum as well as the ultra-violet can be accessed. Due to this lack of wavelength discontinuity these lasers enable a variety of new applications in spectroscopy, forensics, and many other fields.

Jeremy O'Brien

University of Bristol

25th October 2013 

Quantum photonics will deliver disruptive information, communication and sensor technologies by harnessing quantum effects. Of the various approaches to quantum computing, photons are particularly appealing for their low-noise properties and ease of manipulation at the single qubit level. Prof O'Brien will report efforts to develop the key components—single photon sources and detectors, and reconfigurable waveguide circuits—and their integration and address issues surrounding.

Tim Birks

University of Bath

18th October 2013 

Astrophotonics is the application of photonics technology to solve problems in observational astronomy. In this talk, Prof Birks will describe how optical fibres are being developed to filter out unwanted IR emissions from the Earth's atmosphere, which hampers ground-based observations of the early Universe.

Peter Hore

University of Oxford

11th October 2013 

Migratory birds travel spectacular distances each year, navigating and orienting by a variety of means, most of which are poorly understood. Among them is a remarkable ability to perceive the intensity and direction of the Earth's magnetic field. Biologically credible mechanisms for the sensing of such weak fields (25-65 microtesla) are scarce and in recent years just two proposals have emerged as frontrunners. One, essentially classical, centres on iron-containing particles. The other relies on the magnetic sensitivity of short-lived radical pairs formed by photoinduced electron transfer. This model b! egan to attract interest following the proposal that the necessary photochemistry could take place in the bird's retina in specialised photoactive proteins called cryptochromes. The coherent dynamics of electron-nuclear spin states of pairs of radicals is conjectured to lead to changes in the yields of reaction products even though the Zeeman interaction with the geomagnetic field is more than six orders of magnitude smaller than kT. 
In this seminar, Prof Hore will outline some of the experimental evidence for the cryptochrome hypothesis, discuss the interpretation of the reported effects of weak (nanotesla) radiofrequency fields on the magnetic orientation of European robins, and comment on the extent to which cryptochromes are fit-for-purpose as magnetoreceptors.

  Jocelyn Monroe

Royal Holloway, University of London

4th October 2013 

The nature of dark matter is one of the fundamental questions in physics today. A world-wide race is on to directly observe dark matter particles interacting in terrestrial detectors. A number of experiments have recently claimed to detect dark matter interactions, via both direct and indirect experimental methods, although none are yet independently confirmed. The DEAP/CLEAN collaboration is developing a novel approach to dark matter detection, using very large Liquid Argon detectors instrumented with photomultiplier tubes to observe scintillation light from! dark matter scatters in the detector. This design strategy emphasizes scalability to target masses of order 100 tons. This talk will discuss dark matter detection, review recent results from around the world, and describe the experimental technique and status of the DEAP/CLEAN experiment.

TERAHERTZ SPECTROSCOPY OF NANOMATERIALS

 

   Michael Johnston  

University of Oxford

14th June 2013  

Optical-pump terahertz probe spectroscopy is an ideal technique for studying the electronics properties of nanomaterials. In this talk, Dr Johnston will introduce this non-contact method of characterising materials, before presenting recent terahertz conductivity measurements on semiconductor nanowires, graphene and metal oxides. The large surface area to volume ratio of these nanomaterials can be used to tailor their electronic properties for future device applications. 

GAMMA-RAY BURSTS: THE MOST ENERGETIC COSMIC EXPLOSIONS SINCE THE BIG BANG

 

   Ed van den Heuvel  

University of Amsterdam

7th June 2013  

Gamma-ray bursts were discovered with American spy satellites in 1967, but their nature and origin remained a mystery for 30 years. In 1997, thanks to a small Italian-Dutch satellite, it was discovered that they originate at large cosmological distances and result from extremely powerful cosmic explosions, marking the death events of very massive stars. Probably they are the birth events of stellar-mass black holes, although also other explanations remain possible. 

SOLID-STATE QUANTUM OPTICS

 

   Mark Fox  

University of Sheffield

31st May 2013  

Quantum optics describes the interaction between light and matter at the quantum level. The subject developed primarily from atomic physics, but in recent years the scope has expanded widely to include many solid-state systems as well. This has occurred to such an extent that some of the best examples of quantum-optical effects are now observed in the solid state. 

Semiconductor quantum dots provide an excellent system for exploring solid-state quantum-optical phenomena on account of their large optical dipole moment and easy incorporation into advanced photonic devices. In this colloquium, Prof Fox will illustrate some of the quantum-optical phenomena that can be observed from quantum dots, and then explain how these effects can be enhanced by coupling the dots to high quality-factor resonant cavities. 

ELECTRO-OPTIC SENSING FOR DEFENCE AND SECURITY

 

   Richard Hollins  

Dstl

24th May 2013  

The seminar will show how Dstl investigates and exploit new electro-optic sensing to meet the ever-changing needs of defence and security. Activity in a variety of fields including counter-terrorism, optical communications, and sensor protection will be described. The talk will try to illustrate how Dstl conceives and investigates solutions to defence and security challenges by harnessing new technologies emerging from industry and academia.  

INTERFEROMETRY WITH BOSE-EINSTEIN CONDENSATES

 

   Erling Riis  

University of Strathclyde

17th May 2013  

Progress is reviewed on experiments studying the interference of Bose-Einstein condensates (BECs). Using an optical barrier in an elongated magnetic trap we have obtained clear interference fringes for condensates separated by macroscopic distances. 

Current work includes the development of an inductively coupled ring trap intended for Sagnac interferometry. This trap configuration has the potential for being scaled to a size compatible with integration in chip-scale interferometers. Recent progress will also be detailed on the development of planar diffractive optical elements for the generation of the beams required for a magneto-optic trap with a view to realise simple chip-based sources of ultra-cold atoms. 

NEARLY 100 YEARS AFTER GENERAL RELATIVITY: WAS EINSTEIN RIGHT? 
    an answer by a radio astronomer

 

   Michael Kramer  

Max-Planck-Institute for Radio Astronomy

3rd May 2013  

Nearly 100 years ago Einstein proposed a radical change in the understanding of gravity. Since then his theory of general relativity (GR) withstood all tests. Today, we see apparent phenomena that may be explainable by deviations from GR, and hence the question whether Einstein was right, is as topical as ever. This talk will present the some of the latest and best tests of theories of gravity using radio pulsars. 

MECHANICAL ATOM MANIPULATION: TOWARDS A MATTER COMPILER?

 

   Philip Moriarty  

University of Nottingham

26th April 2013  

 

Can we design and construct a matter compiler? That is, is it possible to conceive of a scheme whereby the fundamental atomic/molecular building blocks of matter can be autonomously and intelligently manipulated via software to form a nanoscopic, microscopic, or even macroscopic product? This is the essence of the highly controversial “molecular manufacturing” concept put forward by K. Eric Drexler in the eighties (and which was originally inspired by Feynman’s musings on the ultimate limits of miniaturisation in 1959).

 

In this talk, Prof Moriarty will first reappraise Drexler’s matter compilation scheme in the context of the latest developments in (sub)atomic resolution scanning probe microscopy (SPM) before describing some of his recent work in three areas of key relevance to the matter compilation concept: 
• Atom switching and manipulation driven purely by the making and breaking of a single chemical bond; 
• Probe engineering – tuning the atomic structure of a scanning probe microscope tip by controlled pick-up and reorientation of a C60 molecule; 
• Automated probe microscopy via evolutionary optimization at the atomic scale.

PULSED LASER-ASSISTED GENERATION OF NOVEL MATERIALS AND RELATED APPLICATIONS

 

   Emmanuel Stratakis  

University of Crete

15th March 2013  

This talk will review recent work on the application of pulsed laser processing for novel materials production. Two distinct approaches are reviewed including laser materials modification in controlled gas and liquid media respectively. In particular, it is shown that the artificial surfaces obtained by femtosecond laser texturing of solid surfaces in reactive gas atmosphere exhibit roughness at both micro- and nano-scales that mimics the hierarchical morphology of natural surfaces. Depending on the functional coating deposited on the laser patterned three dimensional structures, artificial surfaces that may be achieved are: (a) of extremely low surface energy, thus water repellent and self-cleaned; (b) responsive, i.e., show the ability to change their surface energy in response to different external stimuli such as light, electric field and pH. The behaviour of different kinds of cells cultured on laser engineered substrates of various morphologies was investigated. The second part of the talk will be focused on the pulsed laser assisted synthesis and functionalization of new types of nanomaterials for organic electronics. Results on the formation of plasmonic nanoparticles, using pulsed laser ablation in liquid media will be presented. Furthermore, rapid and facile methodologies for the photochemical reduction, doping and functionalization of graphene oxide (GO) sheets, based on pulsed UV laser processing of GO, will be demonstrated. Potential applications of laser synthesized and modified materials in organic electronics, particular to bulk heterojunction organic solar cells are demonstrated and discussed. 

PRE-COOLED AIRBREATHING ENGINES: A NEW GENERATION OF HIGH-SPEED PROPULSION

 

   Alan Bond  

Reaction Engines Ltd

8th March 2013  

Liquid hydrogen is an excellent coolant with a very high heat capacity. It has proved possible to design airbreathing engines using this fuel to reach Mach 5 within the limitations of currently available materials and engineering technology. In combination with other engine types, eg rocket or fan, a whole range of propulsion options are possible which will shrink the world to less than 5 hours to anywhere and enable an aircraft to fly into space to do a job and then return to repeat it again within a few hours. 

MOLECULES AND ELECTRONS ILLUMINATE COMPLEX NANOPHOTONICS STRUCTURES

 

   Riccardo Sapienza  

King's College, London

1st March 2013  

Numerous optical technologies and quantum optical devices rely on the controlled coupling of a local emitter to its photonic environment, which is governed by the local density of optical states (LDOS). Light spontaneous emission, absorption and scattering are all related to the LDOS which can be engineered in dielectric and metallic nano structures. Dr Sapienza will present how a nano-sized light probe can illuminate complex materials and shed light on their optical properties and modes. 

This talk will also report nanoscale mapping of the local density of states by cathodo-luminescence microscopy, a combination of electron-beam scanning and optical spectroscopy that relies on scanning a transient dipolar emitter induced by electron beam bombardment with respect to its photonic environment while measuring the total emitted power. Each individual electron traversing the photonic structure generates a nanoscale transient dipole by the accelerated charge which we exploit as a local probe of the LDOS. With unprecedented resolution (~10 nm), localized photonic crystal cavity modes are imaged in a nano-structured silicon nitride membrane, over the visible spectrum into the near-IR, and individual cavity modes are identified that are spatially different and we map their LDOS. Measurements also reveal extended Bloch modes that are delocalized over the crystal and periodically modulated. Moreover, by momentum spectroscopy, angular emission pattern of the radiation emitted, which exhibits complex diffraction patterns, is resolved.

Dr Sapienza will also discuss recent studies of fluorescence from a nano-sized emitter embedded in complex photonic media, such as photonic crystals and random powders, using fluorescence dynamics to measure LDOS distributions in 3D disordered dielectric powders and observing a surprisingly long-tailed distribution of the LDOS with Purcell factor up to ~10. He will discuss how these experimental results fed the ongoing discussion on the dependence of the C0 correlation function on macroscopic disorder parameters. 

THE JOURNEY IN THE SEARCH FOR THE HIGGS BOSON IN CMS AT THE LHC

 

   Tejinder (Jim) Virdee  

CERN & Imperial College, London

8th February 2013  

The LHC accelerator has collided protons and lead ions at unprecedented high energies. It has delivered an integrated luminosity of ~5 pb-1 at √s=7 TeV and ~20 fb-1 at √s=8 TeV to the general-purpose experiments ATLAS and CMS. 

In July 2012, both experiments reported the discovery of a new Higgs-like boson. This talk will outline some of the challenges faced during the construction of the CMS experiment, its operation and performance, and selected physics results. In particular recent results relating to the Higgs-like boson will be discussed as well as the outlook. 

COLD ION CRYSTALS FOR QUANTUM COMPUTING AND QUANTUM SIMULATION

 

   Ferdinand Schmidt-Kaler  

University of Mainz

18th January 2013  

Long-lived states in trapped ions are well suited for implementing quantum information processes, by generating entangled states in linear ion crystals. All the essential building blocks of quantum interactions have been demonstrated, but future challenges need multiple ionic quantum bits in versatile geometric configurations. Prof Schmidt-Kaler will describe how the state-of-the-art may be extended by combining ion entanglement operations with rapid changes of the ion positions for fast transport and modifications of ion configurations in two-dimensional crystal arrays. 

For a scalable quantum computer, Prof Schmidt-Kaler's group is following an approach proposed by Nobel laureate Dave Wineland, whereby ions are transported in a multi-segmented trapping device. To optimize the scheme, ultra-fast ion transport has been achieved without motional excitation at the destination, allowing non-classical quantum states of motion to be generated.

A second important application of trapped ions is quantum simulation, and Prof Schmidt-Kaler will outline the formation and precise investigation of planar zig-zag ion crystals, in which the traversal of a symmetry-breaking phase transition can lead to separated regions with incompatible symmetries and the formation of defects at their boundaries. Such defect formation follows universal scaling laws prescribed by the Kibble-Zurek mechanism, which are observed in the clean model system of trapped ions. Ions in planar crystals may be employed also for simulating spin-spin interactions in frustrated geometries, highly relevant for the observation of unexplored quantum phases and transitions. 

CARBON GEOSTORAGE - THE MONITORING CHALLENGE:
INFLATION, MUONS AND THE MOON

 

   Jon Gluyas  

Durham University

11th January 2013  

The first few carbon storage programmes have begun with dense phase CO2 being injected deep into porous and permeable sites; comparable to the natural traps in which oil and gas occur. Legislation as well as good, common sense dictates that the carbon dioxide once injected needs to be monitored – possibly for generations. Many of the tools used to find and monitor production of petroleum can be used to monitor carbon storage sites but a combination of the timeframes involved and the fact that storage of CO2 does not intrinsically create value (it is waste disposal) mean that a suite of new, low cost, passive, continuous monitoring technologies are require.

Here Prof Gluyas will examine two technologies which have the potential to help monitor both injection and storage of CO2 continuously and at a cost lower than the conventional methods used by the petroleum industry. These have hitherto have not been used by the emerging CCS industry.

InSAR satellite technology has been used to measure changes in elevation, surface inflation, associated with injection of CO2 into the deep subsurface at In Salah in the bare desert of Algeria but how do you apply it to onshore areas that are not bare deserts but rural areas in which a ploughed field or annual vegetation growth could mask changes in elevation of underlying bedrock? Prof Gluyas will present some early results.

The theoretical feasibility of using muon tomography for continuous monitoring of injection of supercritical carbon dioxide into deep geological storage for carbon storage as a climate change mitigation technology has been proven already. Although theoretically feasible it is essential to take the next step and prove its practical feasibility. As a first practical test of feasibility we are using the deep Boulby Potash Mine in northern England provides us with a unique environment in which to measure muon fluxes, develop and deploy instrumentation and test the sensitivity of our method. The mine extends offshore and provides the ideal location for the ultimate sensitivity test. Might it be possible to detect the diurnal and monthly tidal cycles from deep within the mine using muon detectors?

ASTRONOMY BY MICROSCOPE

 

   Monica Grady  

Open University

7th December 2012  

Traditionally, astronomers study stars and planets by telescope. But we can also learn about them by using a microscope – through studying meteorites. From meteorites, we can learn about the processes and materials that shaped the Solar System and our planet. Tiny grains within meteorites have come from other stars, giving information about the stellar neighbourhood in which the Sun was born.

Meteorites are fragments of ancient material, natural objects that survive their fall to Earth from space. Some are metallic, but most are made of stone. They are the oldest objects that we have for study. Almost all meteorites are fragments from asteroids, and were formed at the birth of the Solar System, approximately 4570 million years ago. They show a compositional variation that spans a whole range of planetary materials, from completely unmelted and unfractionated stony chondrites to highly fractionated and differentiated iron meteorites. Meteorites, and components within them, carry records of all stages of Solar System history. There are also meteorites from the Moon and from Mars that give us insights to how these bodies have formed and evolved.

In her lecture, Prof Grady will describe how the microscope is another tool that can be employed to trace stellar and planetary processes. 

EXPLORING THE QUANTUM SUPERPOSITION PRINCIPLE WITH MACROMOLECULES AND MOLECULAR CLUSTERS

 

   Markus Arndt  

University of Vienna

30th November 2012  

Quantum delocalization and quantum interference with massive matter have puzzled physicists for decades since these phenomena question our common understanding of reality, locality or space-time. Recent experimental advances have allowed us to devise new molecular sources, interferometer arrangements and detection methods that open the path to testing quantum mechanics at the interface to philosophy. At the same time modern particle interferometers generate a flying molecular nanostructure which acts as a fine rule for sensitive force measurements with applications in physical chemistry.  

CLOUDSPOTTING AND WAVE-WATCHING

 

   Gavin Pretor-Pinney  

author; founder of the Cloud Appreciation Society

23rd November 2012  

Gavin Pretor-Pinney, founder of The Cloud Appreciation Society, is the author of the bestselling Cloudspotter's Guide and Cloud Collector's Handbook. More recently, he wrote The Wavewatcher's Companion, which won the 2011 Royal Society Winton Prize for Science Books. In it, he reminded us that ocean waves, so familiar to us all, are just a tiny proportion of the many waves that surround us, pass through us, and shape our experience of the world. Sound waves, light waves, microwaves, Mexican waves – it is easy to forget they are waves at all. Waves also have a great bearing on our atmosphere: from the way light waves are diffracted and refracted by the water droplets and crystals to produce glorious halo phenomena to the way sound waves seem to travel further in foggy conditions as they are bent by the low cold air; from the standing waves of air that cause lenticularis clouds to appear in the lee of mountain peaks to the shearing winds that lead to beautiful undulatus and Kelvin-Helmholtz wave formations. So important are waves to our experience of our surroundings that it is only natural for a cloudspotter to be a wavewatcher too. 

THE ANTARCTIC OZONE HOLE AND ITS DISCOVERY

 

   Jonathan Shanklin  

British Antarctic Survey

9th November 2012  

The talk will outline the scientific steps leading up to the discovery of the Antarctic ozone hole and follow its subsequent evolution, as well as illustrating the Antarctic environment. Climate change and the ozone hole interact, but whilst international measures to combat ozone depletion are working, those designed to reduce emissions of other greenhouse gases are finding less ready acceptance. Dr Shanklin will conclude by pointing out a common cause linking these and other environmental issues. 

CRYSTAL STRUCTURE ENGINEERING IN NANOWIRES

 

   Erik Bakkers  

Eindhoven University of Technology

2nd November 2012  

Important semiconductors like Si, Ge and GaP cannot be used for optical devices, since they have an indirect bandgap when having the (normal) cubic crystal structure. It has been predicted that when these materials crystallize in a hexagonal structure that they can have a direct bandgap. But, these materials have never been made with the wurtzite structure. Nanowires can be grown in other crystal structures than known in the bulk, offering new routes to tailor the optical and electronic properties. Prof Bakkers will discuss the nanowire growth mechanism, investigations of the fabrication of the pure hexagonal form, and the control of the nanowire crystal structure that these possibilities permit. Finally, he will demonstrate the direct nature of the bandgap of wurtzite GaP, which is promising to boost the efficiency of white-emitting LEDs. 

RING-SHAPED TRAPS FOR ATOM-INTERFEROMETRY

 

   Paul Griffin  

University of Strathclyde

19 October 2012  

Atom interferometry offers significant benefits to the field of precision metrology due to the sensitivity to external electromagnetic fields and inertial forces, whilst permitting significantly longer interaction times compared to optical sensors. The Strathclyde group has been manipulating atoms in ring traps for over a decade, with the goal of harnessing the sensitivity of massive quantum particles - atoms - for next-generation sensors. In this talk, Dr Griffin will give an introduction the power of atom interferometry and describe the Strathclyde group’s approach, which uses some old physics to overcome previous limitations and to push towards a precise measurement of the fine-structure constant. 

THE TECHNICAL EXAMINATION AND ANALYSIS OF OLD MASTER DRAWINGS

 

   David Saunders  

British Museum

12 October 2012  

Although the technical examination of easel paintings is a well-developed field, various constraints have made it much more difficult to apply similar methods to the examination of Old Master drawings. This talk will look briefly at the issues associated with investigating drawings and watercolours and present the techniques that are used. The results that can be obtained will be illustrated through case studies on Italian Renaissance drawings and English Elizabethan watercolours conducted at the British Museum over the last five years, including as-yet-unpublished findings from a late-sixteenth century map of North America. 

NAVIGATING TO THE MOON - CHALLENGES FACED BY APOLLO 11

 

   Pat Norris  

Logica (formerly TRW/Apollo moon landing program)

15 June 2012  

The first manned lunar landing was a close run thing - Neil Armstrong burned up most of Apollo 11's spare fuel avoiding the rugged terrain NASA had mistakenly navigated him to. Pat Norris was involved in preparing the Apollo 11 navigation and will explain how advances in timing, geodesy and gravity were needed to make the Apollo missions a success - Armstrong presented him with the Apollo Individual Achievement Award for his contribution to the success.

PHYSICS AND TECHNOLOGY OF HIGH-ENERGY LINEAR ELECTRON-POSITRON COLLIDERS

 

   Phil Burrows  

John Adams Institute, University of Oxford

8 June 2012  

A high-energy electron-positron collider would provide a facility for exploitation of major physics discoveries expected at the Large Hadron Collider at CERN, for example via a 'Higgs boson factory'. The International Linear Collider (ILC) is the most mature design and is aimed at energies of 500-1000 GeV. The Compact Linear Collider (CLIC) is based on a novel 'two-beam' acceleration scheme and targets potentially higher energies, up to multi-TeV. Prof Burrows will review the physics potential of such colliders and discuss the technology challenges along the road to their realisation. 

IDENTIFICATION AND NON-DESTRUCTIVE STATE DETECTION OF MOLECULAR IONS

 

   Matthias Keller  

University of Sussex

25 May 2012  

Cold molecules have applications ranging from high resolution spectroscopy and tests of fundamental theories to cold chemistry and, potentially, quantum information processing. Prerequisite for these applications is the cooling of the molecules’ motion and its non-invasive identification. Furthermore, the internal state of the molecules needs to be prepared and non-destructively detected.

The cooling of the motion and trapping of molecular ions can be accomplished by trapping them in an rf-trap alongside laser cooled atomic ions. Dr Keller will describe a novel technique to measure the average charge-to-mass ratio of trapped ions, which has been employed to observe charge exchange reactions between calcium isotopes, and to characterize the trap anharmonicity with precision. The method is limited only by the required interrogation time and the motional coupling of the constituents of the mixed ion crystal. By employing state-selective laser-induced dipole forces, Dr Keller's group aims to detect the internal state of molecular ions by mapping the state information onto the ions' motion. The scheme promises mitigation of a number of experimental artefacts and may be applicable to large numbers of simultaneously trapped molecules. 

BFG COMPOSITE ROTATIONS: PRECISE CONTROL IN AN IMPRECISE WORLD

 

   Jonathan Jones  

University of Oxford

18 May 2012  

Quantum information processing technologies are notoriously vulnerable to the effects of errors. These include not only random errors (decoherence) but also systematic errors arising from experimental imperfections. Composite rotations, originally developed in NMR where they are called composite pulses, provide an effective way of tackling systematic errors in many cases, allowing precise control of quantum systems with ordinary imprecise equipment. After a simple introduction to the basic ideas, Prof Jones will describe BB1 composite rotations, and finally the recently discovered family of BFG rotations which allows extreme tolerance of errors in certain cases. 

IS QUANTUM THEORY EXACT? 
Collapse models and the possibility of a breakdown of quantum mechanics towards the macroscopic scale

 

   Angelo Bassi  

University of Trieste

11 May 2012  

This talk will review the problems quantum mechanics encounters when describing measurement situations (more generally, the quantum-to-classical transition) and the solutions which have been proposed so far. Dr Bassi will focus on one such solution: models of spontaneous wave function collapse. He will describe their general features and discuss the lower and upper bounds on their parameters, before reviewing their status as phenomenological modifications of quantum mechanics, whose predictions can be tested experimentally.

COSMOLOGY IN OUR BACKYARD

 

   Carlos Frenk  

Durham University

4 May 2012  

The LCDM cosmological model accounts for an impressive array of data on the large-scale structure of the universe. On submegaparsec scales, however, the model cannot be tested with the same degree of rigour as on larger scales where microwave background radiation data and measures of galaxy clustering provide clean and well-understood diagnostics. Yet, it is precisely on these small scales that the nature of the dark matter manifests itself most clearly. Prof Frenk will discuss theoretical predictions for the small-scale structure of the universe which appear to be discrepant with recent kinematical data for satellite galaxies of the Milky Way. Possible solutions range from exotic baryonic processes to the more radical assumption that the dark matter is not what the standard theory assumes. 

NANOPLASMONIC FIELD-ENHANCED HIGH HARMONIC GENERATION AT MHz REPETITION RATES

 

   Sarah Stebbings  

Max Planck Institute for Quantum Optics

27 April 2012  

Laser driven high harmonic generation is a well established technique for the production of attosecond pulses in the extreme ultraviolet (XUV). In this talk, Dr Stebbings will present the different approaches employed in order to generate trains of and isolated attosecond XUV pulses at MHz repetition rates. These sources have potential to open up new applications in lithography, nanoplasmonics, high-precision spectroscopy and time-resolved coincidence experiments. 

QUANTUM NANOPHOTONICS

 

   Peter Lodahl  

University of Copenhagen

20 April 2012  

Nanophotonics structures such as photonic crystals or plasmon nanostructures have in recent years proven to provide a very efficient way of enhancing the local interaction between light and matter enabling all-solid-state quantum electrodynamics experiments. This talk will review recent progress on 2D photonic crystal membranes containing quantum dots for photon emission control, and discuss how a highly efficient and triggered single-photon source can be constructed by coupling single quantum dots to a photonic crystal waveguide by exploiting slow light. The role of disorder in the form of fabrication imperfections is explored and found to lead to Anderson localization of light enabling cavity quantum electrodynamics by exploiting disorder as a way to enhance light-matter interactions. Finally, it will be demonstrated that the mesoscopic character of quantum dot emitters implies that the traditional point-dipole description of light-matter interaction may break down in plasmonic nanostructures, providing a new way to strongly interface photons with matter. 

PEPTIDE-FUNCTIONALISED NANOMATERIALS FOR BIOSENSING AND OTHER APPLICATIONS

 

   Molly Stevens  

Imperial College, London

9 March 2012  

This talk will cover the Imperial College group's recent work in the design of peptide-functionalised nanoparticles responsive to a plethora of different enzymes. Self-assembling materials can also be utilised successfully in regenerative medicine as will be illustrated here. 

ORGANIC SEMICONDUCTORS: LIGHTING UP THE FUTURE

 

   Ifor Samuel  

University of St Andrews

2 March 2012  

Organic semiconductors are of growing importance as optoelectronic materials. This talk will introduce the materials and show examples of emerging applications. These include the use of organic light-emitting diodes to enable skin cancer treatment, and the detection of explosive vapour using organic semiconductor lasers. 

POSITRON ANNIHILATION IN MOLECULES

 

   Gleb Gribakin  

Queen's University, Belfast

24 February 2012  

It has been known since 1950's that positron annihilation rates in many polyatomic molecules can be orders of magnitude greater than estimates based on Dirac's electron-positron annihilation rate. This phenomenon remained one of the major puzzles of positron physics for decades. Dr Gribakin's talk will review the results of concerted efforts by experiment and theory over the past ten years, which have provided much understanding and revealed many interesting details.

As we now know, the enhancement of positron annihilation is caused by positron capture in vibrational Feshbach resonances. This capture is facilitated by the ability of the positron to bind to many neutral atomic and molecular species. The annihilation probability is further enhanced by processes of intramolecular vibrational energy redistribution which increases the positron resonant trapping time.

NOVEL ION TRAPS FOR DETERMINISTIC ION IMPLANTATION AND QUANTUM SIMULATION

 

   Kilian Singer  

University of Mainz

17 February 2012  

Novel geometries of ion traps allow the deterministic, high resolution implantation of individual laser-cooled ions, and can operate with a huge range of sympathetically cooled ion species, isotopes or ionic molecules. They therefore offer the basis of an atomic nano-assembler - a novel device capable of placing an exactly defined number of atoms or molecules with millikelvin energies into solid state substrates with sub-nanometre precision in depth and lateral position.

Motivated by the general quest for novel tailored solid-state quantum materials, the Mainz group's major goal is the deterministic generation of colour centres or quantum dots that can be placed in special geometries to exploit their mutual coupling for the realization of macroscopic functional systems and interfaced to the macroscopic world with the help of electrode structures, single electron transistors and optical micro-cavities. Current state-of-the-art production techniques are incapable of such structures, posing a major production problem for the realization of scaled solid-state quantum devices. Targeted applications range from quantum repeaters, correlated triggered multi-photon sources and calibrated single photon sources to quantum computation circuits and sensors with unprecedented sensitivity.

Dr Singer will also present new planar and three-dimensional trap geometries which allow for the application of variable rf fields for precise positioning of ions in two dimensions. These geometries are of great interest for realizing two-dimensional ion crystals with controllable interactions, and enable novel schemes for the quantum simulation of solid-state spin systems with laser-cooled trapped ions. Dr Singer will also present a novel trap design for the realization of a thermodynamic heat engine with a single ion; simulations and the experimental setup will be shown.

SATELLITE-BASED RESEARCH ON PLANETARY WAVES IN THE OCEAN

 

   Paolo Cipollini  

National Oceanography Centre, University of Southampton

10 February 2012  

We know from Carl-Gustav Rossby's 1930s theory of planetary waves that they should exist not only in the atmosphere (where they are easily seen) but also in the oceans. However, until the advent of precise satellite altimetry in the 1990s, there was very scarce observational evidence. Altimetry has confirmed that these long-wavelength, westward-propagating internal waves are common in the tropical and mid-latitude ocean, where they accompany the ubiquitous non-linear eddies, and that they travel faster than expected – so theoreticians have had to make some adjustments to the theory. But then we started looking in other global satellite-derived datasets (SST, ocean colour), and the signature of eddies and waves is also clearly visible there - implying that these westward-propagating phenomena affect the heat balance and the biology. All these new observations have opened a number of intriguing questions that are not only important for our full understanding of ocean dynamics, but also linked to climate change and the carbon cycle.

In this talk, Dr Cipollini will review what we know, explain what are the many issues still open in this field of research, that need to be tackled with an integrated, interdisciplinary effort, and provide an update on recent work carried out at the National Oceanography Centre on this topic.

NEXT-GENERATION QUANTUM COMPUTERS

 

   Mike Brownnutt  

University of Innsbruck

20 January 2012  

Schrödinger bemoaned the fact that one could never perform experiments on single atoms. Nonetheless, in the 20 years since quantum computing was first proposed we have shown that we can actually do exactly that; we have superb control of single atoms, and can perform a variety of basic computational operations on them. Unfortunately, we now face the inverse problem: a computer does consist of single atoms, but of many hundreds or thousands of atoms (at least)! After reviewing how far quantum computing has been carried to date using trapped ions, Dr Brownnutt will look at the question, “Where do we go from here?” What steps must be taken to take the “ridiculous consequences” of quantum mechanics which Schrödinger feared, and preserve them even as we scale computers to such sizes that they are useful? Achieving this scaling in trapped-ion systems requires a radical rethink of how we make and operate traps, but will pave the way to the next generation of quantum computers. 

PHYSICS MEETS BIOLOGY: THE PHYSICAL PROPERTIES OF THE CELL MEMBRANE

 

   Peter Winlove  

University of Exeter

13 January 2012  

Research at the interface between physical science and biology is developing rapidly and studies on the cell membrane demonstrate the importance of this multidisciplinary approach. The textbook view of the membrane as “proteins floating in a sea of phospholipids” (Singer and Nicholson (1970)) fails to address important issues such as the diversity of lipids found in the membrane. We shall begin by discussing studies on Langmuir monolayers of phospholipids which explore the physics of interactions between lipid classes and with cytoskeletal proteins. We shall then introduce novel techniques for measuring the unique mechanical properties of the membrane and present evidence of changes in red cell mechanics that may be important in disease. Finally we shall discuss the complex electrical properties of the membrane, their characterisation by means of fluorescence microscopy, and their importance in membrane function and dysfunction.

The Large Synoptic Survey Telescope
Ian Shipsey University of Oxford                                                            31st October 2014

 

Technological advances have made possible the deep optical survey of a large fraction of the visible sky, enabling the search for small moving objects in the solar system, studies of the assembly history of the Milky Way, the exploration of transient sky, and the establishment of tight constraints on models of dark energy. With an 8.4 m primary mirror, and a 3.2 Gigapixel, 10 deg2 CCD camera, LSST will provide nearly an order of magnitude improvement in survey speed, and is expected in its first month of operation to survey more of the optical universe than all previous telescopes built by mankind.

 

In ten years, the LSST will survey half of the sky in six optical colors down to 27th magnitude, revealing four billion new galaxies and 10 million supernovae. LSST will produce 15 terabytes of data per night, processed by dedicated computing facilities in near real time. Prof Shipsey will discuss some of the science that will be made possible by the construction of LSST, especially dark energy science, which constitutes a profound challenge to particle physics and cosmology, and give an overview of the technical design and current status of the project.

We use cookies to ensure that we give you the best experience on our website. If you continue without changing your settings, we will assume that you are happy to receive cookies on the University of Southampton website.

×