Comparing the Overhead of Topological and Concatenated Quantum Error Correction
Total Page:16
File Type:pdf, Size:1020Kb
Load more
Recommended publications
-
Simulating Quantum Field Theory with a Quantum Computer
Simulating quantum field theory with a quantum computer John Preskill Lattice 2018 28 July 2018 This talk has two parts (1) Near-term prospects for quantum computing. (2) Opportunities in quantum simulation of quantum field theory. Exascale digital computers will advance our knowledge of QCD, but some challenges will remain, especially concerning real-time evolution and properties of nuclear matter and quark-gluon plasma at nonzero temperature and chemical potential. Digital computers may never be able to address these (and other) problems; quantum computers will solve them eventually, though I’m not sure when. The physics payoff may still be far away, but today’s research can hasten the arrival of a new era in which quantum simulation fuels progress in fundamental physics. Frontiers of Physics short distance long distance complexity Higgs boson Large scale structure “More is different” Neutrino masses Cosmic microwave Many-body entanglement background Supersymmetry Phases of quantum Dark matter matter Quantum gravity Dark energy Quantum computing String theory Gravitational waves Quantum spacetime particle collision molecular chemistry entangled electrons A quantum computer can simulate efficiently any physical process that occurs in Nature. (Maybe. We don’t actually know for sure.) superconductor black hole early universe Two fundamental ideas (1) Quantum complexity Why we think quantum computing is powerful. (2) Quantum error correction Why we think quantum computing is scalable. A complete description of a typical quantum state of just 300 qubits requires more bits than the number of atoms in the visible universe. Why we think quantum computing is powerful We know examples of problems that can be solved efficiently by a quantum computer, where we believe the problems are hard for classical computers. -
Quantum Information Science and the Technology Frontier Jake Taylor February 5Th, 2020
Quantum Information Science and the Technology Frontier Jake Taylor February 5th, 2020 Office of Science and Technology Policy www.whitehouse.gov/ostp www.ostp.gov @WHOSTP Photo credit: Lloyd Whitman The National Quantum Initiative Signed Dec 21, 2018 11 years of sustained effort DOE: new centers working with the labs, new programs NSF: new academic centers NIST: industrial consortium, expand core programs Coordination: NSTC combined with a National Coordination Office and an external Advisory committee 2 National Science and Technology Council • Subcommittee on Quantum Information Science (SCQIS) • DoE, NSF, NIST co-chairs • Coordinates NQI, other research activities • Subcommittee on Economic and Security Implications of Quantum Science (ESIX) • DoD, DoE, NSA co-chairs • Civilian, IC, Defense conversation space 3 Policy Recommendations • Focus on a science-first approach that aims to identify and solve Grand Challenges: problems whose solutions enable transformative scientific and industrial progress; • Build a quantum-smart and diverse workforce to meet the needs of a growing field; • Encourage industry engagement, providing appropriate mechanisms for public-private partnerships; • Provide the key infrastructure and support needed to realize the scientific and technological opportunities; • Drive economic growth; • Maintain national security; and • Continue to develop international collaboration and cooperation. 4 Quantum Sensing Accuracy via physical law New modalities of measurement Concept: atoms are indistinguishable. Use Challenge: measuring inside the body. Use this to create time standards, enables quantum behavior of individual nuclei to global navigation. image magnetic resonances (MRI) Concept: speed of light is constant. Use this Challenge: estimating length limited by ‘shot to measure distance using a time standard. noise’ (individual photons!). -
American Leadership in Quantum Technology Joint Hearing
AMERICAN LEADERSHIP IN QUANTUM TECHNOLOGY JOINT HEARING BEFORE THE SUBCOMMITTEE ON RESEARCH AND TECHNOLOGY & SUBCOMMITTEE ON ENERGY COMMITTEE ON SCIENCE, SPACE, AND TECHNOLOGY HOUSE OF REPRESENTATIVES ONE HUNDRED FIFTEENTH CONGRESS FIRST SESSION OCTOBER 24, 2017 Serial No. 115–32 Printed for the use of the Committee on Science, Space, and Technology ( Available via the World Wide Web: http://science.house.gov U.S. GOVERNMENT PUBLISHING OFFICE 27–671PDF WASHINGTON : 2018 For sale by the Superintendent of Documents, U.S. Government Publishing Office Internet: bookstore.gpo.gov Phone: toll free (866) 512–1800; DC area (202) 512–1800 Fax: (202) 512–2104 Mail: Stop IDCC, Washington, DC 20402–0001 COMMITTEE ON SCIENCE, SPACE, AND TECHNOLOGY HON. LAMAR S. SMITH, Texas, Chair FRANK D. LUCAS, Oklahoma EDDIE BERNICE JOHNSON, Texas DANA ROHRABACHER, California ZOE LOFGREN, California MO BROOKS, Alabama DANIEL LIPINSKI, Illinois RANDY HULTGREN, Illinois SUZANNE BONAMICI, Oregon BILL POSEY, Florida ALAN GRAYSON, Florida THOMAS MASSIE, Kentucky AMI BERA, California JIM BRIDENSTINE, Oklahoma ELIZABETH H. ESTY, Connecticut RANDY K. WEBER, Texas MARC A. VEASEY, Texas STEPHEN KNIGHT, California DONALD S. BEYER, JR., Virginia BRIAN BABIN, Texas JACKY ROSEN, Nevada BARBARA COMSTOCK, Virginia JERRY MCNERNEY, California BARRY LOUDERMILK, Georgia ED PERLMUTTER, Colorado RALPH LEE ABRAHAM, Louisiana PAUL TONKO, New York DRAIN LAHOOD, Illinois BILL FOSTER, Illinois DANIEL WEBSTER, Florida MARK TAKANO, California JIM BANKS, Indiana COLLEEN HANABUSA, Hawaii ANDY BIGGS, Arizona CHARLIE CRIST, Florida ROGER W. MARSHALL, Kansas NEAL P. DUNN, Florida CLAY HIGGINS, Louisiana RALPH NORMAN, South Carolina SUBCOMMITTEE ON RESEARCH AND TECHNOLOGY HON. BARBARA COMSTOCK, Virginia, Chair FRANK D. LUCAS, Oklahoma DANIEL LIPINSKI, Illinois RANDY HULTGREN, Illinois ELIZABETH H. -
Universal Control and Error Correction in Multi-Qubit Spin Registers in Diamond T
LETTERS PUBLISHED ONLINE: 2 FEBRUARY 2014 | DOI: 10.1038/NNANO.2014.2 Universal control and error correction in multi-qubit spin registers in diamond T. H. Taminiau 1,J.Cramer1,T.vanderSar1†,V.V.Dobrovitski2 and R. Hanson1* Quantum registers of nuclear spins coupled to electron spins of including one with an additional strongly coupled 13C spin (see individual solid-state defects are a promising platform for Supplementary Information). To demonstrate the generality of quantum information processing1–13. Pioneering experiments our approach to create multi-qubit registers, we realized the initia- selected defects with favourably located nuclear spins with par- lization, control and readout of three weakly coupled 13C spins for ticularly strong hyperfine couplings4–10. To progress towards each NV centre studied (see Supplementary Information). In the large-scale applications, larger and deterministically available following, we consider one of these NV centres in detail and use nuclear registers are highly desirable. Here, we realize univer- two of its weakly coupled 13C spins to form a three-qubit register sal control over multi-qubit spin registers by harnessing abun- for quantum error correction (Fig. 1a). dant weakly coupled nuclear spins. We use the electron spin of Our control method exploits the dependence of the nuclear spin a nitrogen–vacancy centre in diamond to selectively initialize, quantization axis on the electron spin state as a result of the aniso- control and read out carbon-13 spins in the surrounding spin tropic hyperfine interaction (see Methods for hyperfine par- bath and construct high-fidelity single- and two-qubit gates. ameters), so no radiofrequency driving of the nuclear spins is We exploit these new capabilities to implement a three-qubit required7,23–28. -
Unconditional Quantum Teleportation
R ESEARCH A RTICLES our experiment achieves Fexp 5 0.58 6 0.02 for the field emerging from Bob’s station, thus Unconditional Quantum demonstrating the nonclassical character of this experimental implementation. Teleportation To describe the infinite-dimensional states of optical fields, it is convenient to introduce a A. Furusawa, J. L. Sørensen, S. L. Braunstein, C. A. Fuchs, pair (x, p) of continuous variables of the electric H. J. Kimble,* E. S. Polzik field, called the quadrature-phase amplitudes (QAs), that are analogous to the canonically Quantum teleportation of optical coherent states was demonstrated experi- conjugate variables of position and momentum mentally using squeezed-state entanglement. The quantum nature of the of a massive particle (15). In terms of this achieved teleportation was verified by the experimentally determined fidelity analogy, the entangled beams shared by Alice Fexp 5 0.58 6 0.02, which describes the match between input and output states. and Bob have nonlocal correlations similar to A fidelity greater than 0.5 is not possible for coherent states without the use those first described by Einstein et al.(16). The of entanglement. This is the first realization of unconditional quantum tele- requisite EPR state is efficiently generated via portation where every state entering the device is actually teleported. the nonlinear optical process of parametric down-conversion previously demonstrated in Quantum teleportation is the disembodied subsystems of infinite-dimensional systems (17). The resulting state corresponds to a transport of an unknown quantum state from where the above advantages can be put to use. squeezed two-mode optical field. -
Quantum Error Modelling and Correction in Long Distance Teleportation Using Singlet States by Joe Aung
Quantum Error Modelling and Correction in Long Distance Teleportation using Singlet States by Joe Aung Submitted to the Department of Electrical Engineering and Computer Science in partial fulfillment of the requirements for the degree of Master of Science in Electrical Engineering and Computer Science at the MASSACHUSETTS INSTITUTE OF TECHNOLOGY May 2002 @ Massachusetts Institute of Technology 2002. All rights reserved. Author ................... " Department of Electrical Engineering and Computer Science May 21, 2002 72-1 14 Certified by.................. .V. ..... ..'P . .. ........ Jeffrey H. Shapiro Ju us . tn Professor of Electrical Engineering Director, Research Laboratory for Electronics Thesis Supervisor Accepted by................I................... ................... Arthur C. Smith Chairman, Department Committee on Graduate Students BARKER MASSACHUSE1TS INSTITUTE OF TECHNOLOGY JUL 3 1 2002 LIBRARIES 2 Quantum Error Modelling and Correction in Long Distance Teleportation using Singlet States by Joe Aung Submitted to the Department of Electrical Engineering and Computer Science on May 21, 2002, in partial fulfillment of the requirements for the degree of Master of Science in Electrical Engineering and Computer Science Abstract Under a multidisciplinary university research initiative (MURI) program, researchers at the Massachusetts Institute of Technology (MIT) and Northwestern University (NU) are devel- oping a long-distance, high-fidelity quantum teleportation system. This system uses a novel ultrabright source of entangled photon pairs and trapped-atom quantum memories. This thesis will investigate the potential teleportation errors involved in the MIT/NU system. A single-photon, Bell-diagonal error model is developed that allows us to restrict possible errors to just four distinct events. The effects of these errors on teleportation, as well as their probabilities of occurrence, are determined. -
Defense Primer: Quantum Technology
Updated June 7, 2021 Defense Primer: Quantum Technology Quantum technology translates the principles of quantum Successful development and deployment of such sensors physics into technological applications. In general, quantum could lead to significant improvements in submarine technology has not yet reached maturity; however, it could detection and, in turn, compromise the survivability of sea- hold significant implications for the future of military based nuclear deterrents. Quantum sensors could also sensing, encryption, and communications, as well as for enable military personnel to detect underground structures congressional oversight, authorizations, and appropriations. or nuclear materials due to their expected “extreme sensitivity to environmental disturbances.” The sensitivity Key Concepts in Quantum Technology of quantum sensors could similarly potentially enable Quantum applications rely on a number of key concepts, militaries to detect electromagnetic emissions, thus including superposition, quantum bits (qubits), and enhancing electronic warfare capabilities and potentially entanglement. Superposition refers to the ability of quantum assisting in locating concealed adversary forces. systems to exist in two or more states simultaneously. A qubit is a computing unit that leverages the principle of The DSB concluded that quantum radar, hypothesized to be superposition to encode information. (A classical computer capable of identifying the performance characteristics (e.g., encodes information in bits that can represent binary -
Phd Proposal 2020: Quantum Error Correction with Superconducting Circuits
PhD Proposal 2020: Quantum error correction with superconducting circuits Keywords: quantum computing, quantum error correction, Josephson junctions, circuit quantum electrodynamics, high-impedance circuits • Laboratory name: Laboratoire de Physique de l'Ecole Normale Supérieure de Paris • PhD advisors : Philippe Campagne-Ibarcq ([email protected]) and Zaki Leghtas ([email protected]). • Web pages: http://cas.ensmp.fr/~leghtas/ https://philippecampagneib.wixsite.com/research • PhD location: ENS Paris, 24 rue Lhomond Paris 75005. • Funding: ERC starting grant. Quantum systems can occupy peculiar states, such as superpositions or entangled states. These states are intrinsically fragile and eventually get wiped out by inevitable interactions with the environment. Protecting quantum states against decoherence is a formidable and fundamental problem in physics, and it is pivotal for the future of quantum computing. Quantum error correction provides a potential solution, but its current envisioned implementations require daunting resources: a single bit of information is protected by encoding it across tens of thousands of physical qubits. Our team in Paris proposes to protect quantum information in an entirely new type of qubit with two key specicities. First, it will be encoded in a single superconducting circuit resonator whose innite dimensional Hilbert space can replace large registers of physical qubits. Second, this qubit will be rf-powered, continuously exchanging photons with a reservoir. This approach challenges the intuition that a qubit must be isolated from its environment. Instead, the reservoir acts as a feedback loop which continuously and autonomously corrects against errors. This correction takes place at the level of the quantum hardware, and reduces the need for error syndrome measurements which are resource intensive. -
Arxiv:0905.2794V4 [Quant-Ph] 21 Jun 2013 Error Correction 7 B
Quantum Error Correction for Beginners Simon J. Devitt,1, ∗ William J. Munro,2 and Kae Nemoto1 1National Institute of Informatics 2-1-2 Hitotsubashi Chiyoda-ku Tokyo 101-8340. Japan 2NTT Basic Research Laboratories NTT Corporation 3-1 Morinosato-Wakamiya, Atsugi Kanagawa 243-0198. Japan (Dated: June 24, 2013) Quantum error correction (QEC) and fault-tolerant quantum computation represent one of the most vital theoretical aspect of quantum information processing. It was well known from the early developments of this exciting field that the fragility of coherent quantum systems would be a catastrophic obstacle to the development of large scale quantum computers. The introduction of quantum error correction in 1995 showed that active techniques could be employed to mitigate this fatal problem. However, quantum error correction and fault-tolerant computation is now a much larger field and many new codes, techniques, and methodologies have been developed to implement error correction for large scale quantum algorithms. In response, we have attempted to summarize the basic aspects of quantum error correction and fault-tolerance, not as a detailed guide, but rather as a basic introduction. This development in this area has been so pronounced that many in the field of quantum information, specifically researchers who are new to quantum information or people focused on the many other important issues in quantum computation, have found it difficult to keep up with the general formalisms and methodologies employed in this area. Rather than introducing these concepts from a rigorous mathematical and computer science framework, we instead examine error correction and fault-tolerance largely through detailed examples, which are more relevant to experimentalists today and in the near future. -
EU–US Collaboration on Quantum Technologies Emerging Opportunities for Research and Standards-Setting
Research EU–US collaboration Paper on quantum technologies International Security Programme Emerging opportunities for January 2021 research and standards-setting Martin Everett Chatham House, the Royal Institute of International Affairs, is a world-leading policy institute based in London. Our mission is to help governments and societies build a sustainably secure, prosperous and just world. EU–US collaboration on quantum technologies Emerging opportunities for research and standards-setting Summary — While claims of ‘quantum supremacy’ – where a quantum computer outperforms a classical computer by orders of magnitude – continue to be contested, the security implications of such an achievement have adversely impacted the potential for future partnerships in the field. — Quantum communications infrastructure continues to develop, though technological obstacles remain. The EU has linked development of quantum capacity and capability to its recovery following the COVID-19 pandemic and is expected to make rapid progress through its Quantum Communication Initiative. — Existing dialogue between the EU and US highlights opportunities for collaboration on quantum technologies in the areas of basic scientific research and on communications standards. While the EU Quantum Flagship has already had limited engagement with the US on quantum technology collaboration, greater direct cooperation between EUPOPUSA and the Flagship would improve the prospects of both parties in this field. — Additional support for EU-based researchers and start-ups should be provided where possible – for example, increasing funding for representatives from Europe to attend US-based conferences, while greater investment in EU-based quantum enterprises could mitigate potential ‘brain drain’. — Superconducting qubits remain the most likely basis for a quantum computer. Quantum computers composed of around 50 qubits, as well as a quantum cloud computing service using greater numbers of superconducting qubits, are anticipated to emerge in 2021. -
Quantum Computing in the NISQ Era and Beyond
Quantum Computing in the NISQ era and beyond John Preskill Institute for Quantum Information and Matter and Walter Burke Institute for Theoretical Physics, California Institute of Technology, Pasadena CA 91125, USA 30 July 2018 Noisy Intermediate-Scale Quantum (NISQ) technology will be available in the near future. Quantum computers with 50-100 qubits may be able to perform tasks which surpass the capabilities of today’s classical digital computers, but noise in quantum gates will limit the size of quantum circuits that can be executed reliably. NISQ devices will be useful tools for exploring many-body quantum physics, and may have other useful applications, but the 100-qubit quantum computer will not change the world right away — we should regard it as a significant step toward the more powerful quantum technologies of the future. Quantum technologists should continue to strive for more accurate quantum gates and, eventually, fully fault-tolerant quantum computing. 1 Introduction Now is an opportune time for a fruitful discussion among researchers, entrepreneurs, man- agers, and investors who share an interest in quantum computing. There has been a recent surge of investment by both large public companies and startup companies, a trend that has surprised many quantumists working in academia. While we have long recognized the commercial potential of quantum technology, this ramping up of industrial activity has happened sooner and more suddenly than most of us expected. In this article I assess the current status and future potential of quantum computing. Because quantum computing technology is so different from the information technology we use now, we have only a very limited ability to glimpse its future applications, or to project when these applications will come to fruition. -
Quantum Information Science
Quantum Information Science Seth Lloyd Professor of Quantum-Mechanical Engineering Director, WM Keck Center for Extreme Quantum Information Theory (xQIT) Massachusetts Institute of Technology Article Outline: Glossary I. Definition of the Subject and Its Importance II. Introduction III. Quantum Mechanics IV. Quantum Computation V. Noise and Errors VI. Quantum Communication VII. Implications and Conclusions 1 Glossary Algorithm: A systematic procedure for solving a problem, frequently implemented as a computer program. Bit: The fundamental unit of information, representing the distinction between two possi- ble states, conventionally called 0 and 1. The word ‘bit’ is also used to refer to a physical system that registers a bit of information. Boolean Algebra: The mathematics of manipulating bits using simple operations such as AND, OR, NOT, and COPY. Communication Channel: A physical system that allows information to be transmitted from one place to another. Computer: A device for processing information. A digital computer uses Boolean algebra (q.v.) to processes information in the form of bits. Cryptography: The science and technique of encoding information in a secret form. The process of encoding is called encryption, and a system for encoding and decoding is called a cipher. A key is a piece of information used for encoding or decoding. Public-key cryptography operates using a public key by which information is encrypted, and a separate private key by which the encrypted message is decoded. Decoherence: A peculiarly quantum form of noise that has no classical analog. Decoherence destroys quantum superpositions and is the most important and ubiquitous form of noise in quantum computers and quantum communication channels.