Satellite meeting organised by Professor Sir Peter Knight FRS, Professor Ian Walmsley FRS, Professor Gerard Milburn, Dr Jonathan Pritchard, Dr Stephen Till.
Satellite meeting organised by Professor Sir Peter Knight FRS, Professor Ian Walmsley FRS, Professor Gerard Milburn, Dr Jonathan Pritchard, Dr Stephen Till.
The satellite meeting has brought together academic and industry leaders in quantum physics and engineering, and focused on the next steps required to facilitate the translation of novel quantum physics for timing, sensing, communications, computing and simulation and facilitate into systems for real world applications.
Speaker biographies, abstracts, and recorded audio of the presentations is available below.
Enquiries: contact the events team.
Compressive sensing utilises sparsity to realise efficient image reconstruction. It is a valuable processing technique when cost, power, technology or computational overhead are limited or high. In the quantum domain technology usually limits efficient acquisition of weak or fragile signals. I will discuss the basics of information theory, compression, and compressive sensing. I will then discuss our recent work in compressive sensing. The topics of discussion include low-flux laser Radar, photonic phase transitions, high resolution biphoton ghost imaging, Ghost object tracking, 3D object tracking and high dimensional entanglement characterisation. I will touch lightly on our current work of rapid wavefunction reconstruction and wavefront sensing. As an example, we were able to efficiently and rapidly reconstruct high dimensional joint probability functions of biphotons in momentum and position. With conventional raster scanning this process would take approximately a year, but using double-pixel compressive sensing, the pictures were acquired in a few hours with modest flux.
The Quantum Communications Hub is part of the UK National Quantum Technologies Programme, focused on secure communications. I will introduce this Hub and give an overview of the technologies we are pursuing: short-range, free-space consumer QKD; chip-scale QKD modules; the UK Quantum Network (UKQN); next generation quantum communications. I'll also introduce an addition to the UKQN which is just underway. I will briefly outline our technology goals for the Hub.
Great strides are being made in the development of quantum optical technologies. Philosophical questions surrounding entanglement have inspired recent loophole free experiments to push the boundaries of collection efficiency and of quantum memory. The technological advances allow us to begin developing novel applications in device independent quantum communications and in sub-shot noise experiments. Similarly integrated quantum photonics has allowed dramatic scaling down of dimensions and increased complexity in circuits for quantum information processing. However ultimate scalability and performance will require deterministic sources and entanglement generation (or gates) which is difficult to engineer in conventional non-linear media but potentially solved using nano-photonic systems coupled to solid state spins.
Quantum simulators seek to allow fundamental insight into the behaviour of complex quantum systems by modelling (or emulating) behaviour of physical systems that cannot be simulated on a classical computer. There has been a lot of progress in recent years in this area across a range of physical systems, including ultracold atomic gases, trapped ions, photons, and more recently also solid state devices. Ultracold atoms, in particular, offer possibilities to perform analogue quantum simulation (or quantum emulation) of lattice and spin models for strongly interacting systems that are usually encountered in solid-state physics. This involves engineering these models directly in an environment where we have microscopic first-principles control over their parameters. Such devices have the potential to act as a quantum mechanical equivalent of wind tunnels for testing ideas in many-body quantum physics, and as experimental challenges are systematically overcome, this has wide ranging potential to contribute to a lot of areas of physics - and science more generally. These areas range from a next generations of quantum technologies for measurement and sensing to potential new insights into materials science and quantum chemistry. I will give an overview of the recent progress in theory and experiment, including the realisation of new ways to measure previously inaccessible quantities such as many-body entanglement, and new means to control, calibrate and verify analogue quantum simulators.
What is the most promising architectural paradigm for a quantum information processor? This question remains open, but I will put the argument for a hybrid matter/light system composed of few-qubit devices interlinked by an optical fabric. After reviewing recent achievements in experiments, theory and applications, I will describe the Q20:20 machine that the Oxford-led National Quantum Hub is building in the UK. The system is 'provably' capable of universal, fault tolerant quantum computing using components already demonstrated, but of course building a full scale machine of that kind would be a massive undertaking. I'll comment on the potential for more immediate impacts as a ‘1st generation’ quantum computer in areas like optimisation, simulation and machine learning.
At the beginning of the industrial revolution thermodynamic laws were formulated to analyse and improve the performance of the newly invented steam engine. These laws have been successfully applied ever since to design a great variety of useful everyday devices, from car engines and fridges to power plants and solar cells. However, the ongoing miniaturisation of many technologies to the nanoscale is expected to soon enter regimes where standard thermodynamic laws do not apply and new theoretical underpinning is required.
I will give a brief introduction to quantum thermodynamics - the emerging research field that aims to uncover the thermodynamic laws that govern small ensembles of systems that follow non-equilibrium dynamics and can host quantum properties. As an example of experimental applications, I will describe our recent non-equilibrium temperature experiment with nanospheres that are levitated in air. I will close with an outlook on technological challenges that are likely to require new quantum thermodynamics input to be resolved.
Modern-day society continues to experience increasing sophistication in the application of quantum technology devices to navigation and timing since the introduction of the caesium atomic clock some 60 years ago. Caesium microwave fountain clocks now realise the SI second at the part in 1016 level within National Measurement Institutes, and cold atom optical clock analogues are already out-performing the fountain clock by 1 – 2 orders of magnitude, thereby offering a route to a redefinition of the second within a decade. Whilst these laboratory-based highest-accuracy clocks offer precision metrology that can contribute to high science and fundamental physics, the spin-out of industrial clock systems has led to increasing applications in timing and navigation with direct bearing on everyday life via satellite navigation, mobile phone synchronisation, energy management and financial trading. Within these sectors, the time and frequency clock capability is generally traded off against devices with much lower size, weight and power (SWaP) specifications, but with the important requirement for robust and resilient operation.
Our leading-edge microwave and optical atomic clocks make use of such techniques as laser cooling, quantum state preparation and super-position and quantum jump read-out. I will describe our activities in exporting similar techniques into low-SWaP clock and timing systems that can benefit the wider timing applications. The use of fountain techniques represents a difficulty for small clock systems because of size issues, but the technologies within trapped ion clocks and neutral atoms optical lattice clocks offer viable routes to miniature and compact clocks in both the microwave and optical regions.
Atom interferometer gravimeters can measure vertical acceleration with very low noise, and excellent absolute accuracy. If the same could be achieved in all three Cartesian directions, one could imagine using this as the basis for an improved inertial navigation system. To realise the benefit of the atom accelerometer, it will also be necessary to have good enough rotation information, and that will require improvements in gyroscopes. Once all this is achieved, variations in the direction and strength of local gravity become a significant source of systematic error. Alternatively, one could consider fine structures in the gravity map as a powerful way to determine position.
I will discuss the technical challenges in building a 3-axis atom-interferometer accelerometer and will summarise the status of this in my laboratory. I will consider inertial navigation systems, touching on the role of Schuler oscillations in mitigating the effect of accelerometer bias. Time permitting, I will mention briefly how atom interferometry can be used to detect dark energy.
Modern cryptography encompasses much more than encryption of secret messages. Signature schemes are widely used to guarantee that messages cannot be forged or tampered with, for example in e-mail, software updates and electronic commerce. Messages are also transferrable, which distinguishes digital signatures from message authentication. Transferability means that messages can be forwarded; in other words, that a sender is unlikely to be able to make one recipient accept a message which is subsequently rejected by another recipient if the message is forwarded.
Similar to public-key encryption, the security of commonly used signature schemes relies on the assumed computational difficulty of problems such as finding discrete logarithms or factoring large primes. With quantum computers, such assumptions would no longer be valid. Partly for this reason, it is desirable to develop signature schemes with unconditional or information-theoretic security. Quantum signature schemes are one possible solution. Similar to quantum key distribution (QKD), their unconditional security relies only on the laws of quantum mechanics. Quantum signatures can be realised with the same system components as QKD, but are so far less investigated. This talk aims to provide an introduction to quantum signatures and to review progress so far.
Quantum physics holds the promise of enhanced performance in metrology and sensing by exploiting non-classical phenomena such as multiparticle interference. Specific designs for quantum-enhanced schemes need to take into account noise and imperfections present in real-life implementations. This talk will review selected recent results in realistic quantum metrology, starting from interferometric phase estimation with common impairments, such as photon loss, and ending with general scaling laws implied by the geometry of quantum channels. In many situations, although qualitatively improved asymptotic scaling of ideal noise-free protocols is lost, quantum physics can usefully offer performance beyond the standard shot noise limit. As a concrete example, a comparison of the fundamental quantum interferometry bound with the recently achieved sensitivity of the squeezed-light-enhanced GEO600 gravitational wave detector indicates its nearly optimal operation given the present amount of optical loss. Finally, the potential of mode-engineering techniques exploiting multiple degrees of freedom to alleviate deleterious effects induced for example by residual distinguishability in multiphoton interference is highlighted.
QUANTIC, in common with the other Quantum Hubs, has been operating its partnership funding scheme for over a year. In that time a number of successful partnership projects with industry have been funded and initiatives have been taken with co-funders to create new opportunities for industry and academia alike. At the same time issues have emerged inter alia from the framework contracts under which the Hubs operate specifically in relation to IP ownership. Some of the plans for national management of IP have yet to come to fruition and the internationalisation agenda for the quantum programme has highlighted some conflicts with UK priorities. This talk will talk about the operation of our partnership programme and the issues that have emerged from implementing it.
The dimensions required for many quantum devices has to be at the nanoscale to enable quantum effects to be engineered. At these length scales surfaces dominate and reproducible nanofabrication is a serious challenge.
I will demonstrate 1D silicon nanowires that demonstrate high quality single electron tunnelling that are being developed with the application of a new quantum based current standard. The challenges of producing clean devices to reduce scattering and techniques to reduce parasitic second order quantum processes will be reviewed.
Next the challenges of producing high performance Ge on Si single photon avalanche detectors will be discussed. These devices are being developed to allow integrated non-linear and quantum photonics all on a silicon platform. Here again surfaces are key along with reducing defect densities. Also key is engineering the technology so that it can be translated to silicon foundries. Recent results using commercial wafers will be presented.
Finally a miniature MEMS device which has been used to measure the gravitational forces from the earth tides will be reviewed where a different set of challenges are key. Such devices can be used for geological prospecting for petrochemicals, early detection of volcano eruptions and a range of security applications. Engineering long term stability over weeks requires thermal and mechanical challenges to be addressed.
Many emerging themes of quantum technology including quantum sensing, quantum imaging, quantum communications, quantum computing and quantum time-keeping and navigation have specific and precise laser source requirements.
In this talk we examine the laser requirements both in terms of specific technical requirements and form factor and usability requirements. We review wavelength accessibility, tuneability and precision control, linewidth requirements, noise considerations and phase-locking of multiple sources alongside a broader description of emerging themes for miniaturisation of lasers for quantum applications.
Precision solid-state lasers based on Ti:Sapphire and Optically-Pumped Semiconductors (OPS) or Vecsels are described along with techniques to achieve tuneability, linewidth and noise control that results in the critical parameters required for demanding quantum applications. Wavelength extension achieving agility of tuning across the spectrum from the deep UV to mid-IR will also be discussed.
Case studies of key results and quantum developments enabled by novel laser technology and our own integration of novel laser sources into quantum subsystems and systems will be reviewed. Current progress on optical and cold atom/ion system miniaturisation and ruggedisation and development of IP-enabled digital control systems to integrate quantum systems will be reported.
The roadmap for future laser requirements and developments will be considered. The evolution of the first generation of quantum instruments is defining requirements for component device and sub-system miniaturisation and systems-level complex control.
Finally a brief review of the emergence of a Quantum Technologies industry and the UK role in this globally emerging market will be analysed.
Ultra-cold matter, in the form of laser-cooled atoms and ions, holds a unique and fertile role in quantum technology with applications from gravitational sensors to quantum simulation. This is due to over three decades of development into producing extremely pure quantum states with highly sophisticated control techniques. Theoretical application of ultra-cold matter are far ahead of experimental capabilities because the apparatus is complex, labour intensive to build and operate, and sensitive to noise and instabilities - even within a laboratory environment. These properties throttle the speed in which ultra-cold quantum physics progresses, but also shackles it to the laboratory and is a major hurdle to industrial appropriation.
Research at the University of Southampton aims to overturn this trend by exploring materials and methods to miniaturise, simplify and economically mass-produce ultra-cold apparatus, specifically the magneto-optical trap which is at the heart of all cold atomic systems. I will discuss our progress into developing ground-breaking micro-litre, and passive, ultrahigh vacuum cells using silicon wafer microfabrication techniques. These methods can also be applied to produce chip-scale vapour cells, as well as atom and ion traps. We are also developing hermetic electrical feedthroughs to supply ‘atom-chips’ and in-vacua electronics with power and also provide integrated viewports. Together with compact stabilised lasers and monolithic optics being developed by the Quantum Technology Hubs, this technology will move toward our ultimate goal of commercial matchbox-sized atomic sensor and clock systems.
Photonics is a promising approach to realising quantum information technologies, where entangled states of light are generated and manipulated to realise fundamentally new modes of computation, simulation and communication, as well as enhanced measurements and sensing. Historically bulk optical elements on large optical tables have been the means by which to realise proof-of-principle demonstrators in quantum physics. More recently, integrated quantum photonics has enabled a step change in this technology by utilising state-of-the-art photonic engineering approach to deliver complex and compact quantum circuits. In this talk, I will give an overview of the challenges and opportunities that integrated quantum photonics present, highlighting recent achievement in chip-to-chip quantum communications, programmable quantum circuits, chip-based quantum simulations and routes to scalable quantum information processing.
The first quantum revolution developed during the first half of the 20th century. First a conceptual revolution, based on wave-particle duality and on a statistical description of large ensembles of microscopic quantum objects, it enabled the technological revolution of the laser, the transistor and integrated circuits, leading to the information society.
The second quantum revolution, which developed in the last decades of the 20th century, is based on entanglement and on the possibility of controlling individual quantum objects. These revolutionary concepts have lead to proposals of quantum technologies: quantum cryptography, simulation, computing, metrology. These ideas are implemented on different quantum systems, either natural (atoms, ions, photons…) or artificial (based on nanofabrication methods).
Will one of these engineering solutions become dominant, or will the winners be hybrid systems? Only a broad collaboration between scientists and engineers in the various fields can bring an answer.
Scientific meeting
09 - 10 May 2016
Scientific discussion meeting organised by Professor Sir Peter Knight FRS, Professor Ian Walmsley FRS, Professor Gerard Milburn, Dr Jonathan Pritchard, Dr Stephen Till.