In the present day there is only one commercial application of quantum information processing (QIP), quantum key distribution, and the market embracing it is small. The development of further applications requires the realisation of a suite of practical devices that are able to create, buffer, process and repeat quantum information. Semiconductor structures have dominated digital information’s history, as their ease of use and scalability are both ideal in meeting market demands. In the Quantum Technology Centre at Lancaster University we are developing semiconductor devices for practical applications of QIP, and in this talk I will discuss our progress.
In the present day there is only one commercial application of quantum information processing (QIP), quantum key distribution, and the market embracing it is small. The development of further applications requires the realisation of a suite of practical devices that are able to create, buffer, process and repeat quantum information. Semiconductor structures have dominated digital information’s history, as their ease of use and scalability are both ideal in meeting market demands. In the Quantum Technology Centre at Lancaster University we are developing semiconductor devices for practical applications of QIP, and in this talk I will discuss our progress.
During the last ten years, superconducting circuits have passed from being interesting physical devices to becoming contenders for near-future useful and scalable quantum information processing (QIP). Advanced quantum simulation experiments have been shown with up to nine qubits, while a demonstration of quantum supremacy with fifty qubits is anticipated in just a few years. Quantum supremacy means that the quantum system can no longer be simulated by the most powerful classical supercomputers. Integrated classical-quantum computing systems are already emerging that can be used for software development and experimentation, even via web interfaces. Therefore, the time is ripe for describing some of the recent development of superconducting devices, systems and applications. As such, the discussion of superconducting qubits and circuits is limited to devices that are proven useful for current or near future applications. Consequently, the centre of interest is the practical applications of QIP, such as computation and simulation in Physics and Chemistry.
The ideas behind Quantum Information Processing (QIP) began to appear about twenty years ago and theoretical developments have been appearing ever since. Over the last decade quantum experiments have begun to realize QIP and point the way towards the routes for future quantum information technology. This review is a simple introduction to QIP for non-experts. It discusses the basic ideas of and the underpinning quantum theory needed to understand them, as well as various applications and algorithms, and some of the main candidate routes for realizing QIP.
The practical implementation of quantum information technologies requires, for the most part, highly advanced and currently experimental procedures. One exception is quantum cryptography, or quantum key distribution, which has been successfully demonstrated in many laboratories and has reached an advanced level of development. It will probably become the first commercial application of quantum information. In quantum key distribution, Alice and Bob exploit a quantum channel to create a secret shared key comprising a random string of binary digits. This key can then be used to protect a subsequent communication between them. The principal idea is that the secrecy of the key distribution is ensured by the laws of quantum physics. Proving security for practical communication systems is a challenging problem and requires techniques that are beyond the scope of this book. At a fundamental level, however, the ideas are simple and may readily be understood with the knowledge we have already acquired. Quantum cryptography is the latest idea in the long history of secure (and not so secure) communications and, if it is to develop, it will have to compete with existing technologies. For this reason we begin with a brief survey of the history and current state of the art in secure communications before turning to the possibilities offered by quantum communications. The history of cryptography is a long and fascinating one. As a consequence of the success or, more spectacularly, the failure of ciphers, wars have been fought, battles decided, kingdoms won, and heads lost. In the information age, ciphers and cryptosystems have become part of everyday life; we use them to protect our computers, to shop over the Internet, and to access our money via an ATM (automated teller machine). One of the oldest and simplest of all ciphers is the transposition or Caesarean cipher (attributed to Julius Caesar), in which the letters are shifted by a known (and secret) number of places in the alphabet. If the shift is 1, for example, then A is enciphered as B, B→C, · · ·, Y→Z, Z→A. A shift of five places leads us to make the replacements A→F, B→G, · · ·, Y→D, Z→E.
(100 Word Limit): Quantum information science promises profoundly disruptive information and communication technologies. Photons are ideal carriers of quantum information: Their low noise, high speed transmission, and ease of manipulation at the single photon level make them indispensable for quantum communication, which offers security based on the laws of physics, quantum metrology, which promises the ultimate precision measurements, and quantum information processing, which promises exponentially greater computational power for particular tasks. Recently integrated optical devices have been applied to these technologies. We give an overview of quantum technologies and progress towards their realisation in integrated optics. Presenter Bio (100 Word Limit): O’Brien is director of the Centre for Quantum Photonics, University of Bristol. His Ph.D. from the University of New South Wales in 2002 was for experimental work on correlated and confined electrons in organic conductors, superconductors and semiconductor nanostructures, and progress towards silicon quantum computing. At the University of Queensland (2001-2006) he worked on quantum optics and quantum information science with photons. CQP’s efforts are focused on the fundamental and applied quantum mechanics at the heart of quantum information science and technology, from prototypes for scalable quantum computing to quantum communication, and quantum metrology.
Quantum computing has been a long-anticipated emerging computational paradigm to complement and compete with conventional CMOS technologies. The last decade has featured reports of the initial development of using CMOS processing techniques for qubits and the atomistic fabrication of single atom transistors. Will the semiconductor industry embrace this new architype, and if so, how? When quantum devices begin to scale as predicted, will our industry be ready to integrate radically different architectures and device structures? Are there known obstacles not yet addressed that would enable the industry to more readily adopt and benefit from today’s achievements in the laboratory? What are the emerging designs and the potential fundamental challenges that are to be overcome? We have assembled a panel of experts that will share their insights on the state-of-the-art in quantum computing as well as intellectual leaders that will share their vision of the eventual merger of these new technologies with our computing capabilities today, even as lithography is approaching the near-atomic domain. Join us as we discuss the impending critical impact of quantum computing on the semiconductor industry.
Abstract Quantum photonic system has made remarkable achievements in computing and communication. Serving as quantum information carriers, photons are flying qubits and robust against decoherence, emerging as a desirable platform to make quantum processor a reality. However, with system's complexity and functionality scaling up, the requirements for stability, programmability, and manufacturability will be in high demand. Integrated photonics, compatible with complementary metal‐oxide‐semiconductor fabrication, has overwhelming dominance in terms of density and performance, making it an unrivaled contender for large‐scale quantum information processing (QIP). To improve the performance of individual blocks and integrate them on a common substrate is one of the core tasks for a practical quantum processor. Here, the recent advances in components that constitute quantum photonic systems on silicon photonics platform, including sources, modulators, and detectors are reviewed. Burgeoning quantum photonics applications, such as multi‐dimensional, multi‐photon QIP and integrated quantum key distribution are highlighted.