quantum information A showcase of cutting-edge research taken from selected journals and Physics World. iopscience.org/quantum-information contents
Introduction 3 Classical and Quantum Gravity 4 EPL 6 Journal of Physics A: Mathematical and Theoretical 8 Journal of Physics B: Atomic, Molecular and Optical Physics 10 Journal of Physics: Condensed Matter 12 New Journal of Physics 14 Physica Scripta 16 Quantum Electronics 18 Reports on Progress in Physics 20 Superconductor Science and Technology 22 Physics World 24 Additional content 26 How to submit your quantum information research 28
Stay updated on quantum information Interested in other areas by visiting the online collection at iopscience.org/quantum-information. of science? Scan this Latest articles, special issues, videos Visit our subject collections homepage to QR code to go directly and news will be posted regularly. explore similar collections in other key topics. to the online collection iopscience.org/subjects quantum information
The development of quantum physics at the beginning of the 20th century provoked both shock and disbelief in the community. It also stimulated a lot of new ideas. The definition of a system that could exist in a multiple number of states ‘entangled’ with each other bred a wealth of novel approaches for handling information.
A hundred years on and research into quantum information continues to yield surprises and inspire yet more fruitful activity, prompting a number of special issues in many of IOP Publishing’s journals. The Quantum Information landing page presents the latest research developments, as well as reviews that place current research in context. Readers can browse by topic from 10 different IOP Publishing journals in subject categories that include:
• Topological quantum computation • Quantum cryptography and communication • Quantum tomography • Quantum simulation • Quantum measurement and open systems • Solid-state quantum computation • Quantum control and engineering • Quantum entanglement and nonlocality The page provides a one-stop portal that ensures optimum visibility for our authors among their peers, and ease of access for our readers to stay up to date with the leading research in a field that continues to fascinate not just in academia but in industry, and resonates with the general public as well.
iopscience.org/quantum-information 3 Classical and Quantum Gravity
ISSN 0264-9381 Classical and Quantum Gravity is the world’s Classicaland QuantumGravity leading journal covering all aspects of gravitational physics and related areas of cosmology, geometry and field theory. Volume 29 Number 1 7 January 2012
An international journal of gravitational physics, cosmology, geometry and field theory The articles selected here represent a focus issue on ‘relativistic quantum information’, including a comprehensive review article, and some interesting original research on optical black hole lasers. The full focus issue is available on our homepage.
iopscience.org/cqg The journal boasts the best peer review in the field, supported by an international editorial board. The scope of the journal includes, but is not limited to: Did you know? Classical general relativity We provide the option of hybrid • Applications of relativity open access publishing. • • Experimental gravitation • Cosmology and the early universe Did you know? • Quantum gravity Supergravity, superstrings and supersymmetry Classical and Quantum Gravity • Mathematical physics publishes Fast Track • Communications, which are short articles of 8 pages or The readership is broad, comprising gravitational fewer, presenting new and theorists and experimentalists in physics, mathematics highly interesting results. and cosmology, and all articles published contain a summary that places the findings in the wider context of gravitational physics.
iopscience.org/cqg
4 iopscience.org/quantum-information FEATURED ARTICLE The black-hole/qubit correspondence: an up-to-date review Leron Borsten et al 2012 Class. Quantum Grav. 22 430743.
Abstract We give a review of the black-hole/qubit correspondence that incorporates not only the earlier results on black hole entropy and entanglement measures, seven qubits and the Fano plane, wrapped branes as qubits andthe attractor mechanism as a distillation procedure, but also newer material including error-correcting codes, Mermin squares, Freudenthal triples and 4-qubit entanglement classification.
MORE HIGH-INTEREST ARTICLES Cosmological quantum entanglement Eduardo Martin-Martinez et al 2012 Class. Quantum Grav. 22 430740
Relativistic quantum information in detectors-field interactions Bei-Lok Hu et al 2012 Class. Quantum Grav. 22 430346
Optical black hole lasers Daniele Faccio et al 2012 Class. Quantum Grav. 22 431687
Fundamental quantum optics experiments conceivable with satellites – reaching relativistic distances and velocities David P Rideout et al 2012 Class. Quantum Grav. 22 436906
) To read the full articles, visit iopscience.org/quantum-information
iopscience.org/quantum-information 5 EPL
In recent years EPL has gained considerable strength in quantum information topics, including visibility and promotion at conferences and workshops and sponsoring of prizes for best posters or for presentations by young researchers at targeted events.
Articles published cover theory and fundamental physics, emerging technologies, communications, optics, cryptography and simulators. Several articles have been selected here to introduce the broad scope available for authors in EPL.
Did you know? Owned by an association of 17 European physical societies, We provide the option of hybrid EPL publishes Letters that cover the broadest range of open access publishing. physics topics and related scientific fields. These short publications are focused towards novel, scientifically significant, emerging and developing areas of science Did you know? including many high-profile topics such as quantum EPL is owned by an assocation simulators, topological insulators, metamaterials, of 17 European physical plasmonics, ferro-electrics/magnetics and rheology. societies. Targeted marketing ensures that the Letters published gain Published in partnership with: recognition within their relevant fields. This is supported on the website, which now hosts several compilation webpages providing authors with easy access to recent articles published relating to their specialist areas. The compilation listing can be found at epljournal.org/compilations.
epljournal.org
6 iopscience.org/quantum-information FEATURED ARTICLE Quantum noise in three-dimensional BRC interferometry B Opanchuk, M Egorov, S Hoffmann, A I Sidorov and P D Drummond 2012 EPL 97 50003
Abstract We develop a theory of quantum fluctuations and squeezing in a three-dimensional Bose-Einstein condensate atom interferometer with nonlinear losses. We use stochastic equations in a truncated Wigner representation to treat quantum noise. Our approach includes the multi-mode spatial evolution of spinor components and describes the many-body dynamics of a mesoscopic quantum system.
MORE HIGH-INTEREST ARTICLES Quantum refrigerator driven by current noise Yi-Xin Chen & Sheng-Wen 2012 EPL 97 40003
Coherent vortex structures in quantum turbulence A W Baggaley, C F Barenghi, A Shukurov and Y A Sergeev 2012 EPL 98 26002
Transversal propagation of helical edge states in quantum spin Hall systems Feng Lu, Yuan Zhou, Jin An and Chang-De Gong 2012 EPL 98 17004
Quantum game of life D Bleh, T Calarco and S Montangero 2012 EPL 97 20012
) To read the full articles, visit iopscience.org/quantum-information
iopscience.org/quantum-information 7 Journal of Physics A: Mathematical and Theoretical
ISSN 1751-8113 Journal of Physics A: Mathematical and Journal of Physics A Theoretical is a major journal of theoretical physics reporting research on the mathematical structures that describe fundamental processes Volume 45 Number 36 14 September 2012 of the physical world and on the analytical, computational and numerical methods for exploring these structures.
The journal’s dedicated quantum mechanics and quantum information theory section publishes high-quality original research articles that cover all aspects of quantum iopscience.org/jphysa information theory, including entanglement, quantum tomography, quantum measurement theory and quantum Worldwide visibility cryptography, communication and computation. For example, the featured article by Wiebe et al shows explicitly more than how to simulate time-dependant sparse Hamiltonian 575,000 evolution on a quantum computer. full-text downloads in 2011 Included in this selection are some of the most high-impact and popular articles in this area that have been published in Journal of Physics A. However, these papers are just a Fast publication sample of the high-quality work we publish in the field of Average receipt to first decision quantum information theory. Visit the journal homepage time in 2011 was to read more. 34 days iopscience.org/jphysa
8 iopscience.org/quantum-information FEATURED ARTICLE Simulating quantum dynamics on a quantum computer Nathan Wiebe, Dominic W Berry, Peter Høyer and Barry C Sanders 2011 J. Phys. A: Math. Theor. 44 445308
Abstract We explicitly show how to simulate time-dependent sparse Hamiltonian evolution on a quantum computer, with complexity that is close to linear in the evolution time. The complexity also depends on the magnitude of the derivatives of the Hamiltonian. We propose a range of techniques to simulate Hamiltonians with badly behaved derivatives. These include using adaptive time steps, adapting the order of the integrators, and omitting regions about discontinuities. The complexity of the algorithm is quantified by calls to an oracle, which yields information about the Hamiltonian, and accounts for all computational resources. We explicitly determine the number of bits of output that this oracle needs to provide, and show how to efficiently perform the required 1-sparse unitary operations using these bits. We also account for discretization error in the time, as well as accounting for Hamiltonians that are a sum of terms that are sparse in different bases.
MORE HIGH-INTEREST ARTICLES Extremal correlations of the tripartite no-signaling polytope Stefano Pironio, Jean-Daniel Bancal and Valerio Scarani 2011 J. Phys. A: Math. Theor. 44 065303
Low-dimensional quite noisy bound entanglement with a cryptographic key Łukasz Pankowski and Michał Horodecki 2011 J. Phys. A: Math. Theor. 44 035301
Constructions and noise threshold of topological subsystem codes Martin Suchara, Sergey Bravyi and Barbara Terhal 2011 J. Phys. A: Math. Theor. 44 155301
Quantumness and entanglement witnesses Paolo Facchi, Saverio Pascazio, Vlatko Vedral and Kazuya Yuasa 2012 J. Phys. A: Math. Theor. 45 105302
) To read the full articles, visit iopscience.org/quantum-information
iopscience.org/quantum-information 9 Journal of Physics B: Atomic, Molecular and Optical Physics
ISSN 0953-4075 JourJournalnal of PhysiPhysicscs B Quantum Information is at the heart of leading Atomic,Molecular research published in Journal of Physics B as and OpticalPhysics we strive to serve the atomic, molecular and
Volume 45 Number 18 28 September 2012 optical physics community. Tutorial Introduction to attosecond delays in photoionization J M Dahlström, A L’Huillier and A Maquet Boasting an impressive portfolio of regular content covering quantum computation, communication, measurement, entanglement, control, engineering, etc, Journal of Physics B regularly highlights current challenges in the field via its special issues series, e.g. “Quantum control theory for
iopscience.org/jphysb coherence and information dynamics”, “Quantum memory”, “Loss of coherence and memory effects in quantum dynamics”. Our “Cold Rydberg gases and ultra-cold plasmas” Did you know? issue also featured some papers on quantum information with Rydberg atoms, demonstrating the immense potential of Most articles acquire over this field and explaining its popularity among our readers. 200 downloads in their first With a distinguished history of over 45 years, we look forward 90 days online. to continuing to track the progress of quantum information as new developments and applications arise. To discover the Fast publication benefits of publishing your research inJournal of Physics B, please visit the journal homepage. 33 days iopscience.org/jphysb (median) receipt to acceptance for Fast Track Communications
10 iopscience.org/quantum-information FEATURED ARTICLE Robust entanglement generation by reservoir engineering C A Muschik, H Krauter, K Jensen, J M Petersen, J I Cirac and E S Polzik 2012 J. Phys. B: At. Mol. Opt. Phys. 45 124021
Summary Following a recent proposal (Muschik et al 2011 Phys. Rev. A 83 052312), engineered dissipative processes have been used for the generation of stable entanglement between two macroscopic atomic ensembles at room temperature (Krauter et al 2011 Phys. Rev. Lett. 107 080503). This experiment included the preparation of entangled states which are continuously available during a time interval of 1 h. Here, we present additional material, further-reaching data and an extension of the theory developed in Muschik et al (2011 Phys. Rev. A 83 052312). In particular, we show how the combination of the entangling dissipative mechanism with measurements can give rise to a substantial improvement of the generated entanglement in the presence of noise.
MORE HIGH-INTEREST ARTICLES Vibronic effects in the spectroscopy and dynamics of C-phycocyanin Jordan M Womick, Brantley A West, Norbert F Scherer and Andrew M Moran 2012 J. Phys. B: At. Mol. Opt. Phys. 45 154016
Keeping a single qubit alive by experimental dynamic decoupling D J Szwer, S C Webster, A M Steane and D M Lucas 2011 J. Phys. B: At. Mol. Opt. Phys. 44 025501
Quantum tomography of the full hyperfine manifold of atomic spins via continuous measurement on an ensemble Carlos A Riofrío, Poul S Jessen and Ivan H Deutsch 2011 J. Phys. B: At. Mol. Opt. Phys. 44 154007
Amplification of quantum discord between two uncoupled qubits in a common environment by phase decoherence Ji-Bing Yuan, Le-Man Kuang and Jie-Qiao Liao 2010 J. Phys. B: At. Mol. Opt. Phys. 43 165503
) To read the full articles, visit iopscience.org/quantum-information
iopscience.org/quantum-information 11 Journal of Physics: Condensed Matter
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ISSN 0953-8984 JourJournalnal of PhysicsPhysics Journal of Physics: Condensed Matter (JPCM) Condensed Matter covers the whole of condensed matter physics and papers may report experimental, theoretical
Volume 24 Number 38 26 September 2012 or simulation studies. As well as regular research papers and Fast Track Communications, the journal boasts authoritative and exciting topical review and special issue programmes.
Quantum information is a key focus area for JPCM and we are looking to expand our coverage in this field. Included in this iopscience.org/jpcm collection are papers on quantum entanglement and solid- state quantum computation. Also highlighted is a topical Fast Track review by R Biele and R D’Agosta on open quantum systems.
Communications JPCM works with you to provide opportunities for extra On average, Fast Track promotion of articles. Authors can write a news item on Communications are published their work to feature in our LabTalk section, located on our within just 49 days of receipt. homepage. Pitched at a level intended for non-experts in the Authors should receive a first field, LabTalk items highlight the key findings of a paper. decision in under 14 days. Authors of JPCM benefit from fast publication times – on Did you know? average regular papers are published within 95 days of receipt and a first decision is made in just 20 days. JPCM articles received 1.4 million iopscience.org/jpcm downloads in 2011
12 iopscience.org/quantum-information FEATURED ARTICLE A stochastic approach to open quantum systems R Biele and R D’Agosta 2012 J. Phys.: Condens. Matter 24 273201
Abstract In this review, we will focus on the so-called stochastic Schrödinger equation. This is useful as a starting point to investigate the dynamics of open quantum systems capable of exchanging energy and momentum with an external environment. We discuss in some detail the general derivation of a stochastic Schrödinger equation and some of its recent applications to spin thermal transport, thermal relaxation, and Bose–Einstein condensation. We thoroughly discuss the advantages of this formalism with respect to the more common approach in terms of the reduced density matrix. The applications discussed here constitute only a few examples of a much wider range of applicability.
MORE HIGH-INTEREST ARTICLES A proposal for implementing an n-qubit controlled-rotation gate with three-level superconducting qubit systems in cavity QED Chui-Ping Yang 2011 J. Phys.: Condens. Matter 23 225702
Non-Markovian dynamics of a biased qubit coupled to a structured bath Congjun Gan, Peihao Huang and Hang Zheng 2010 J. Phys.: Condens. Matter 22 115301
Spin–spin indirect interaction at low-energy excitation in zero-dimensional cavities J A Andrade, A A Aligia and G F Quinteiro 2011 J. Phys.: Condens. Matter 23 215304
Quantum entanglement and criticality of the antiferromagnetic Heisenberg model in an external field Guang-Hua Liu, Ruo-Yan Li and Guang-Shan Tian 2012 J. Phys.: Condens. Matter 24 256002
) To read the full articles, visit iopscience.org/quantum-information
iopscience.org/quantum-information 13 New Journal of Physics
Information, cryptography and computational theories have experienced a revolution since the discovery of quantum physics at the beginning of the last century. Since then, quantum information science has driven the knowledge of quantum mechanics into a range of multi-disciplinary fields with the potential to dramatically improve the acquisition, transmission and processing of information.
New Journal of Physics (NJP) is well established within the quantum information community as a source of outstanding Impact Factor research in cutting-edge areas that reflect the interdisciplinary nature of the field, and spans themes ranging from quantum information theory, quantum simulation and quantum 4.177 engineering to solid-state candidates for practical realisation As listed in 2011 Journal Citation of quantum computers. reports (Thomson Reuters 2012)® The articles selected for this collection provide a flavour of Video abstracts the kind of high-impact articles NJP has published recently in quantum information, and the journal continues to NJP papers with video abstracts commission content in this timely field through its invited focus are read at least three times issue programme, recent relevant additions to which include more than those without. All Topological Quantum Computation, Quantum Tomography, video abstracts published by NJP Optomechanics, and Quantum Simulation. are also featured on the journal’s YouTube page here: Now established as the leading gold open access journal youtube.com/ in physics and with an Impact Factor of 4.177, the ongoing NewJournalofPhysics mission of NJP is to provide free-to-read research of the highest quality for the benefit of the global physics community. Published in partnership with: www.njp.org
14 iopscience.org/quantum-information FEATURED ARTICLE Exponentially enhanced quantum communication rate by multiplexing continuous variable teleportation Andreas Christ, Cosmo Lupo and Christine Silberhorn 2012 New J. Phys. 14 083007 Abstract A major challenge of today’s quantum communication systems lies in the transmission of quantum information with high rates over long distances in the presence of unavoidable losses. Thereby the achievable quantum communication rate is fundamentally limited by the amount of energy that can be transmitted per use of the channel. It is hence vital to develop quantum communication protocols that encode quantum information as energy efficiently as possible. To this aim we investigate continuous-variable quantum teleportation as a method of distributing quantum information. We explore the possibility to encode information on multiple optical modes and derive upper and lower bounds on the achievable quantum channel capacities. This analysis enables us to benchmark single-mode versus multi-mode entanglement resources. Our research reveals that multiplexing does not only feature an enhanced energy efficiency, leading to an exponential increase in the achievable quantum communication rates in comparison to single-mode coding, but also yields an improved loss resilience. However, as reliable quantum information transfer is only achieved for entanglement values above a certain threshold a careful optimization of the number of coding modes is needed to obtain the optimal quantum channel capacity.
MORE HIGH-INTEREST ARTICLES Quantum entanglement distribution using a magnetic field sensor M Schaffry C Benjamin and Y Matsuzaki 2012 New J. Phys. 14 023046
Engineering integrated pure narrow-band photon sources E Pomarico, B Sanguinetti, C I Osorio, H Herrmann and R T Thew 2012 New J. Phys. 14 033008
Experimental demonstration of quantum gain in a zero-sum game C Zu, Y-X Wang, X-Y Chang, Z-H Wei, S-Y Zhang and L-M Duan 2012 New J. Phys. 14 033002
Driven-dissipative preparation of entangled states in cascaded quantum-optical networks K Stannigel, P Rabl and P Zoller 2012 New J. Phys. 14 063014
) To read the full articles, visit iopscience.org/quantum-information
iopscience.org/quantum-information 15 Physica Scripta
ISSN 0031-8949 Published on behalf of the Royal Swedish Academy of Sciences, Physica Scripta is an
An international journal for experimental and theoretical physics international journal run by scientists to provide
Volume 86 Number 3 September 2012 A journal of the Royal Swedish Academy of Sciences published by IOP Publishing original research across a broad range of physics www.physica.org topics and related areas, with special interest in interdisciplinary and applied research.
The journal also maintains a program of Topical Issues, published separately from the regular journal, which contain invited presentations and/or poster contributions from international conferences, symposia or workshops that highlight cutting-edge research across key areas of physics. Presentations from the annual Nobel Physics Symposium are Did you know? frequently published as a Topical Issue. Acceptance to online publication Key Topical issues published for quantum information 25 days included papers from Nobel Symposia 141 and 148 and from a sequence of annual Central European Workshops on Quantum Optics (15th through 18th). Several articles selected Global visibiity for this booklet are taken from those Topical Issues. Physica Scripta is strong in quantum information, communication, optics, and associated topics covering the broad scope from 250 000 theory to experiment. full-text downloads in 2011 physica.org Published in partnership with: The Royal Swedish Academy of Sciences
16 iopscience.org/quantum-information FEATURED ARTICLE Hybrid quantum devices and quantum engineering M Wallquist et al 2009 Phys. Scr. T137 014001
Abstract We discuss prospects of building hybrid quantum devices involving elements of atomic and molecular physics, quantum optics and solid-state elements with the attempt to combine advantages of the respective systems in compatible experimental setups. In particular, we summarize our recent work on quantum hybrid devices and briefly discuss recent ideas for quantum networks. These include interfacing of molecular quantum memory with circuit QED, and using nanomechanical elements strongly coupled to qubits represented by electronic spins, as well as single atoms or atomic ensembles.
MORE HIGH-INTEREST ARTICLES Quantum information processing and quantum control with trapped atomic ions D J Wineland 2009 Phys. Scr. T137 014007
Entanglement and discord in two-mode Gaussian open quantum systems Aurelian Isar 2012 Phys. Scr. T147 014015
Entanglement dynamics of two independent cavity-embedded quantum dots B Bellomo et al 2011 Phys. Scr. T143 014004
Manipulating and probing microwave fields in a cavity by quantum non-demolition photon counting S Haroche et al 2009 Phys. Scr. T137 014014
) To read the full articles, visit iopscience.org/quantum-information
iopscience.org/quantum-information 17 Quantum Electronics
Established alongside the first publication of the Russian journal Kvantovaya Elektronika in 1971, the English translation Quantum Electronics is produced just a few weeks after each original edition, providing efficient access to unique research from more than 300 world- class Russian institutions and specialists from 25 countries.
Quantum Electronics is the only journal that provides comprehensive results in topics such as quantum electronic devices, laser physics and optics, the interaction of laser Content alerts radiation with matter, and the transmission and processing of information at basic and applied research levels. It is a Register for the Table of Contents valuable resource for those working with all aspects of laser alerts for Quantum Electronics research or with the practical application of laser technologies to receive information about new articles published in the journal in the metrological, biological and medical fields, or in the straight to your inbox. electronics, engineering, defence and materials industries.
Go to iopscience.org/qe and With an Editorial Board and council consisting of more than create an account with 40 world-class experts, the journal also covers laser plasmas, My IOPscience. nonlinear optical phenomena, nanotechnologies, fibre and integrated optics, and active media, and continues to build Published in partnership with: on the strong foundation established by Nobel Prize Laureate Nikolay G Basov.
iopscience.org/qe
18 iopscience.org/quantum-information FEATURED ARTICLE All-optical loadable and erasable memory cell design based on inversionless lasing and electromagnetically induced transparency effects N Gholipour Verki, A Hajibadali, K Abbasian and A Rostami 2011 Quantum Electron. 41 1114
Abstract A loadable and erasable all-optical memory cell is designed by using two coupled micro-ring resonators with electromagnetically induced transparency (EIT) and lasing without inversion (LWI). To read out stored data, an additional phase is introduced in the upper ring resonator due to EIT. To compensate the fibre loss, use is made of LWI. The EIT is induced by inserting Ë-type three level quantum dots in the right-hand half of the upper ring and LWI is implemented by inserted Y-type four level quantum dots in the left-hand half of both rings. This optical memory cell can operate at a low light power level corresponding to several photons.
MORE HIGH-INTEREST ARTICLES Dynamics of ionisation and entanglement in the ‘atom + quantum electromagnetic field’ system P R Sharapova and O V Tikhonova 2012 Quantum Electron. 42 199
Two-electron pulses of a photomultiplier and two-photon photoeffect M V Lebedev, A A Shchekin and O V Misochko 2008 Quantum Electron. 38 710
Dependence of emergence of the collapse and revival effect of Doppler — Rabi osciallations on the initial state of the moving-atom — electromagnetic-field system A V Kozlovskii 2010 Quantum Electron. 40 223
Excitation of coherent polaritons in a two-dimensional atomic lattice I O Barinov, A P Alodzhants and S M Arakelian, 2009 Quantum Electron. 39 685
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iopscience.org/quantum-information 19 Reports on Progress in Physics
ISSN 0034-4885 Reports on Guided exclusively by its prestigious editorial Progress board, Reports on Progress in Physics (ROPP) in Physics has a long-established reputation as one of the
Volume 75 Number 7 July 2012 world’s most authoritative review journals in physics.
An essential resource for physicists at all stages of their careers, the broad appeal of the journal lies in its unique article requirements, as well as a coverage geared to serving all the most vital areas of physics.
iopscience.org/ropp Recognizing the wide-reaching and ongoing interdisciplinary importance of quantum information research, the articles Impact Factor we have selected for this collection give a taste of the kind of seminal reviews that have appeared in ROPP over recent years on themes ranging from quantum channel capacities and 14.720 quantum simulation, through to quantum technologies and As listed in 2011 Journal Citation solid-state quantum computation. reports (Thomson Reuters 2012)® iopscience.org/ropp Key issue reviews Our Key Reviews identify and address burning questions in physics, especially where ultimate significance is still a matter for dispute.
20 iopscience.org/quantum-information FEATURED ARTICLE Physical implementation of protected qubits B Douçot and L B Ioffe 2012 Rep. Prog. Phys. 75 072001
Abstract We review the general notion of topological protection of quantum states in spin models and its relation with the ideas of quantum error correction. We show that topological protection can be viewed as a Hamiltonian realization of error correction: for a quantum code for which the minimal number of errors that remain undetected is N, the corresponding Hamiltonian model of the effects of the environment noise appears only in the Nth order of the perturbation theory.
We discuss the simplest model Hamiltonians that realize topological protection and their implementation in superconducting arrays. We focus on two dual realizations: in one the protected state is stored in the parity of the Cooper pair number, in the other, in the parity of the flux number. In both cases the superconducting arrays allow a number of fault-tolerant operations that should make the universal quantum computation possible.
MORE HIGH-INTEREST ARTICLES Quantum channels and their entropic characteristics A S Holevo and V Giovannetti 2012 Rep. Prog. Phys. 75 046001
Experimental quantum simulations of many-body physics with trapped ions Ch Schneider, Diego Porras and Tobias Schaetz 2012 Rep. Prog. Phys. 75 024401
Natural and artificial atoms for quantum computation Iulia Buluta, Sahel Ashhab and Franco Nori 2011 Rep. Prog. Phys. 74 104401
Diamond-based single-photon emitters I Aharonovich, S Castelletto, D A Simpson, C-H Su, A D Greentree and S Prawer 2011 Rep. Prog. Phys. 74 076501
) To read the full articles, visit iopscience.org/quantum-information
iopscience.org/quantum-information 21 Superconductor Science and Technology
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ISSN 0953-2048 Superconductor Science and Technology Superconductor Superconductor Science and Technology Science and Technology (SUST) is leading the way in developing a fully functional quantum computer. SUST is Vol 25, No 4 045001–049501 Volume 25 Number 4 April 2012 publishing work at the forefront of this Featured article Magneto-optical imaging of superconducting MgB2 joints P Mikheenko, V V Yurchenko and T H Johansen technology and with a high impact factor and fast publication times, there is no better time to publish your next superconducting paper with us.
The journal covers theories of superconductivity, the basic physics of superconductors, the relation of microstructure
April 2012 iopscience.org/sust and growth to superconducting properties, the theory of novel devices, and the fabrication and properties of thin Did you know? films and devices. It also encompasses the manufacture and properties of conductors, and their application in the Each article published in construction of magnets and heavy current machines, Superconductor Science and together with enabling technology. Technology in 2011 was downloaded on average over Authors who publish with us will benefit from: • High visibility: SUST articles were downloaded 250 times 250,000 times in 2011 • Fair and thorough peer-review process: supported by a Fast publication dedicated Editorial Board consisting of leading members in the community The average publication time for High impact: articles from SUST have received coverage a Rapid Communication is just • in global media outlets including Scientific American, CERN Courier, Science Daily and R&D Magazine 64 days • Open access: authors who are required to publish their research as open access can do so for a one-off author payment
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22 iopscience.org/quantum-information FEATURED ARTICLE Superconducting qubits: poised for computing? I Siddiqi 2011 Supercond. Sci. Technol. 24 091002
Abstract Since the first demonstration of coherent oscillations a little over a decade ago, rapid progress in the development of superconducting qubits has resulted in more than a thousand fold increase in coherence times, coupled qubit operation, single-shot readout, and the basic demonstration of quantum algorithms. The operation and state-of-the art of these devices are reviewed. Areas of current growth are also discussed.
MORE HIGH-INTEREST ARTICLES Phenomenological noise model for superconducting qubits: two-state fluctuators and 1/f noise Dong Zhou and Robert Joynt 2012 Supercond. Sci. Technol. 25 045003
Sub-micrometer epitaxial Josephson junctions for quantum circuits Jeffrey S Kline, Michael R Vissers, Fabio C S da Silva, David S Wisbey, Martin Weides, Terence J Weir, Benjamin Turek, Danielle A Braje, William D Oliver, Yoni Shalibo, Nadav Katz, Blake R Johnson, Thomas A Ohki and David P Pappas 2012 Supercond. Sci. Technol. 25 025005
Wirebond crosstalk and cavity modes in large chip mounts for superconducting qubits J Wenner, M Neeley, Radoslaw C Bialczak, M Lenander, Erik Lucero, A D O’Connell, D Sank, H Wang, M Weides, A N Cleland and John M Martinis 2011 Supercond. Sci. Technol. 24 065001
Phase qubits fabricated with trilayer junctions M Weides, R C Bialczak, M Lenander, E Lucero, Matteo Mariantoni, M Neeley, A D O’Connell, D Sank, H Wang, J Wenner, T Yamamoto, Y Yin, A N Cleland and J Martinis 2011 Supercond. Sci. Technol. 24 055005
) To read the full articles, visit iopscience.org/quantum-information
iopscience.org/quantum-information 23 Physics World
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physicsworld.com Volume 25 No 8 August 2012 Physics World is the perfect way for you to stay on top thanks to its timely, accessible and thought- provoking articles from the world’s leading physicists and science writers.” Matin Durrani, Editor
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physicsworld.com physicsworld.com lets you stay up to date with the latest breakthroughs in physics thanks to a unique blend of daily news, a lively blog, thought-provoking webinars and video interviews with some of the world’s leading physicists.
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24 iopscience.org/quantum-information Quantum computing...with a twist Steve Simon explains how a remarkable link between knot theory and certain quantum systems may be useful for quantum information processing.
The quantum game of life The idea that our universe can be modelled as a giant computer dates back to the 1970s. But as Pablo Arrighi and Jonathan Grattage describe, quantum-information theorists are now hoping to revitalize this idea by making the “digital physics” project compatible with quantum theory.
Quantum mechanics in popular science In this podcast the Physics World editorial team discusses why books about quantum mechanics remain so resolutely popular.
) All featured articles are available to read at iopscience.org/quantum-information
iopscience.org/quantum-information 25 Additional content
Chinese Physics Letters Chinese Physics Letters, published in partnership with the Chinese Physical Society, is charged with providing rapid publication of short reports and important research in all fields of physics. The journal provides its diverse readership with coverage of major advances in all aspects of physics, including the newest and most important achievements of physicists in China as well as other parts of the world. Articles included in this selection have achieved a high number of citations since publication and highlight the exceptional quality of research published in the journal. In partnership with: Chinese Physical Society iopscience.org/cpl
Chinese Physics B Widely recognized as one of China’s top journals, Chinese Physics B continues to publish research papers in all areas of theoretical and applied physics, reflecting the high quality and wide scope of Chinese research. The journal’s broad focus makes it an important source of current research in physics, materials, acoustics, mechanics, optics, engineering and biophysics. iopscience.org/cbp
In partnership with: Chinese Physical Society Communications in Theoretical Physics Published monthly, Communications in Theoretical Physics (CTP) is available to the international research community on behalf of the Institute of Theoretical Physics of the Chinese Academy of Sciences and the Chinese Physical Society, and has been in publication for 30 years. CTP is devoted to reporting new developments in theoretical physics, and covers topics in many interdisciplinary areas. iopscience.org/ctp
In partnership with: Institute of Theoretical Physics of the Chinese Academy of Sciences
26 iopscience.org/quantum-information IOP Conference Series IOP Conference Series offers a fast, versatile and cost-effective proceedings publishing service, the coverage of which extends across all materials science disciplines, encompassing analysis, development and application (within the field of quantum information, recent content has covered topics such as optical properties, electromagnetism and nanofabrication). Proceedings volumes are open access and provide a permanent and free-to-read record of an entire conference, from plenary to poster papers. Some forthcoming volumes include the proceedings of ICPEAC XXVII, LT26 and M2S 2012.
conferenceseries.iop.org For more information on these journals visit iopscience.org/quantum-information
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iopscience.org/quantum-information 27 How to submit your quantum information research
Inspired by all this great research and want your work to be included within our online quantum information collection? Here are our recommendations for successfully submitting your paper to an IOP Publishing journal.
Plan Consider the best way to structure your article before you start. Some journals have templates available to assist you in this process, so check this before you begin. Choose a title that best serves your needs – an eye-catching one to attract as many readers as possible, or a descriptive one to engage readers with a specific interest in your area. Give some thought to your abstract. It should very concisely describe the contents of your paper, and encourage readers to view the entire paper. No jargon or undefined abbreviations should be used.
Writing Be clear and concise. Consider the readership of your chosen journal, bearing in mind the knowledge expected of that audience. All content of your paper should be relevant to your main scientific result.
Editing Reconsider your original plan. You may decide to rewrite portions of your paper to improve clarity and conciseness. You should repeat these processes over several successive drafts if necessary. Once the draft is ready to be submitted to a journal, carry out one final spelling and grammar check before submission.
Submission All of our journals operate a fast online submission system. Simply visit the journal homepage and click on the ‘Submit an article’ link. This will take you through to our online submission pages, where you will need to follow the steps described.
To help early career researchers prepare their papers for publication, we have published a digital brochure ‘Introductory guide for authors’ available at iopscience.org/author-guide.
28 iopscience.org/quantum-information IOP subject collections
Browse the IOP subject collections for must-read research in a selection of rapidly growing fields.
• Read the very best research published in IOP journals • Access relevant articles and multimedia from our magazines and websites, including Physics World • Bookmark the collections to keep track of work published by other research groups in your field
The collections include: graphene biomedical engineering
metamaterials semiconductors
The IOP subject collections are available at iopscience.org/subjects Article evolution is a new and ongoing project, which improves the online delivery of research articles on IOPscience, enabling you to interact with research in new ways. The first step in this project has provided the functionality for you to view new articles on IOPscience as an HTML page. Many new features are available, such as being able to zoom in and out of images and viewing video abstracts. MathJax technology has been incorporated, improving the rendering of mathematics, and a mobile view of abstract and article pages is also available.
Find out more at articleevolution.org.
Figure browser Article navigator Improved export option The image browser tab enables you to This contains the article contents list, which You can export content so that you can quickly browse and move to all of the provides you with a list of articles that users refer back to it easily at a later date. fi gures within the article. have also read, a list of related review articles and other useful weblinks.
Image tools – zoom and export References and citations MathJax for PowerPoint Tabs are attached on the left side of the Following our sponsorship of the MathJax You can zoom in and out of an image to article to give you instant access to reference project, you can use MathJax to render study complex structures. You can also and citation lists. mathematics within an article, improving export fi gures to PowerPoint slides for use its readability on the screen. in presentations. the jobs site for physics and engineering
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