TY - JOUR T1 - Quantum-centric Supercomputing for Materials Science: A Perspective on Challenges and Future Directions Y1 - 2023 A1 - Yuri Alexeev A1 - Maximilian Amsler A1 - Paul Baity A1 - Marco Antonio Barroca A1 - Sanzio Bassini A1 - Torey Battelle A1 - Daan Camps A1 - David Casanova A1 - Young jai Choi A1 - Frederic T. Chong A1 - Charles Chung A1 - Chris Codella A1 - Antonio D. Corcoles A1 - James Cruise A1 - Alberto Di Meglio A1 - Jonathan Dubois A1 - Ivan Duran A1 - Thomas Eckl A1 - Sophia Economou A1 - Stephan Eidenbenz A1 - Bruce Elmegreen A1 - Clyde Fare A1 - Ismael Faro A1 - Cristina Sanz Fernández A1 - Rodrigo Neumann Barros Ferreira A1 - Keisuke Fuji A1 - Bryce Fuller A1 - Laura Gagliardi A1 - Giulia Galli A1 - Jennifer R. Glick A1 - Isacco Gobbi A1 - Pranav Gokhale A1 - Salvador de la Puente Gonzalez A1 - Johannes Greiner A1 - Bill Gropp A1 - Michele Grossi A1 - Emmanuel Gull A1 - Burns Healy A1 - Benchen Huang A1 - Travis S. Humble A1 - Nobuyasu Ito A1 - Artur F. Izmaylov A1 - Ali Javadi-Abhari A1 - Douglas Jennewein A1 - Shantenu Jha A1 - Liang Jiang A1 - Barbara Jones A1 - Wibe Albert de Jong A1 - Petar Jurcevic A1 - William Kirby A1 - Stefan Kister A1 - Masahiro Kitagawa A1 - Joel Klassen A1 - Katherine Klymko A1 - Kwangwon Koh A1 - Masaaki Kondo A1 - Doga Murat Kurkcuoglu A1 - Krzysztof Kurowski A1 - Teodoro Laino A1 - Ryan Landfield A1 - Matt Leininger A1 - Vicente Leyton-Ortega A1 - Ang Li A1 - Meifeng Lin A1 - Junyu Liu A1 - Nicolas Lorente A1 - Andre Luckow A1 - Simon Martiel A1 - Francisco Martin-Fernandez A1 - Margaret Martonosi A1 - Claire Marvinney A1 - Arcesio Castaneda Medina A1 - Dirk Merten A1 - Antonio Mezzacapo A1 - Kristel Michielsen A1 - Abhishek Mitra A1 - Tushar Mittal A1 - Kyungsun Moon A1 - Joel Moore A1 - Mario Motta A1 - Young-Hye Na A1 - Yunseong Nam A1 - Prineha Narang A1 - Yu-ya Ohnishi A1 - Daniele Ottaviani A1 - Matthew Otten A1 - Scott Pakin A1 - Vincent R. Pascuzzi A1 - Ed Penault A1 - Tomasz Piontek A1 - Jed Pitera A1 - Patrick Rall A1 - Gokul Subramanian Ravi A1 - Niall Robertson A1 - Matteo Rossi A1 - Piotr Rydlichowski A1 - Hoon Ryu A1 - Georgy Samsonidze A1 - Mitsuhisa Sato A1 - Nishant Saurabh A1 - Vidushi Sharma A1 - Kunal Sharma A1 - Soyoung Shin A1 - George Slessman A1 - Mathias Steiner A1 - Iskandar Sitdikov A1 - In-Saeng Suh A1 - Eric Switzer A1 - Wei Tang A1 - Joel Thompson A1 - Synge Todo A1 - Minh Tran A1 - Dimitar Trenev A1 - Christian Trott A1 - Huan-Hsin Tseng A1 - Esin Tureci A1 - David García Valinas A1 - Sofia Vallecorsa A1 - Christopher Wever A1 - Konrad Wojciechowski A1 - Xiaodi Wu A1 - Shinjae Yoo A1 - Nobuyuki Yoshioka A1 - Victor Wen-zhe Yu A1 - Seiji Yunoki A1 - Sergiy Zhuk A1 - Dmitry Zubarev AB -

Computational models are an essential tool for the design, characterization, and discovery of novel materials. Hard computational tasks in materials science stretch the limits of existing high-performance supercomputing centers, consuming much of their simulation, analysis, and data resources. Quantum computing, on the other hand, is an emerging technology with the potential to accelerate many of the computational tasks needed for materials science. In order to do that, the quantum technology must interact with conventional high-performance computing in several ways: approximate results validation, identification of hard problems, and synergies in quantum-centric supercomputing. In this paper, we provide a perspective on how quantum-centric supercomputing can help address critical computational problems in materials science, the challenges to face in order to solve representative use cases, and new suggested directions.

UR - https://arxiv.org/abs/2312.09733 ER - TY - JOUR T1 - Phase-engineered bosonic quantum codes JF - Physical Review A Y1 - 2021 A1 - Linshu Li A1 - Dylan J Young A1 - Victor V. Albert A1 - Kyungjoo Noh A1 - Chang-Ling Zou A1 - Liang Jiang AB -

Continuous-variable systems protected by bosonic quantum codes have emerged as a promising platform for quantum information. To date, the design of code words has centered on optimizing the state occupation in the relevant basis to generate the distance needed for error correction. Here, we show tuning the phase degree of freedom in the design of code words can affect, and potentially enhance, the protection against Markovian errors that involve excitation exchange with the environment. As illustrations, we first consider phase engineering bosonic codes with uniform spacing in the Fock basis that correct excitation loss with a Kerr unitary and show that these modified codes feature destructive interference between error code words and, with an adapted “two-level” recovery, the error protection is significantly enhanced. We then study protection against energy decay with the presence of mode nonlinearities …

VL - 103 U4 - 062427 UR - https://authors.library.caltech.edu/109764/2/1901.05358.pdf CP - 6 ER - TY - JOUR T1 - Quantum coding with low-depth random circuits Y1 - 2020 A1 - Michael Gullans A1 - Stefan Krastanov A1 - David A. Huse A1 - Liang Jiang A1 - Steven T. Flammia AB -

Random quantum circuits have played a central role in establishing the computational advantages of near-term quantum computers over their conventional counterparts. Here, we use ensembles of low-depth random circuits with local connectivity in D≥1 spatial dimensions to generate quantum error-correcting codes. For random stabilizer codes and the erasure channel, we find strong evidence that a depth O(logN) random circuit is necessary and sufficient to converge (with high probability) to zero failure probability for any finite amount below the channel capacity for any D. Previous results on random circuits have only shown that O(N1/D) depth suffices or that O(log3N) depth suffices for all-to-all connectivity (D→∞). We then study the critical behavior of the erasure threshold in the so-called moderate deviation limit, where both the failure probability and the distance to the channel capacity converge to zero with N. We find that the requisite depth scales like O(logN) only for dimensions D≥2, and that random circuits require O(N−−√) depth for D=1. Finally, we introduce an "expurgation" algorithm that uses quantum measurements to remove logical operators that cause the code to fail by turning them into either additional stabilizers or into gauge operators in a subsystem code. With such targeted measurements, we can achieve sub-logarithmic depth in D≥2 spatial dimensions below capacity without increasing the maximum weight of the check operators. We find that for any rate beneath the capacity, high-performing codes with thousands of logical qubits are achievable with depth 4-8 expurgated random circuits in D=2 dimensions. These results indicate that finite-rate quantum codes are practically relevant for near-term devices and may significantly reduce the resource requirements to achieve fault tolerance for near-term applications. 

UR - https://arxiv.org/abs/2010.09775 ER - TY - JOUR T1 - Development of Quantum InterConnects for Next-Generation Information Technologies Y1 - 2019 A1 - David Awschalom A1 - Karl K. Berggren A1 - Hannes Bernien A1 - Sunil Bhave A1 - Lincoln D. Carr A1 - Paul Davids A1 - Sophia E. Economou A1 - Dirk Englund A1 - Andrei Faraon A1 - Marty Fejer A1 - Saikat Guha A1 - Martin V. Gustafsson A1 - Evelyn Hu A1 - Liang Jiang A1 - Jungsang Kim A1 - Boris Korzh A1 - Prem Kumar A1 - Paul G. Kwiat A1 - Marko Lončar A1 - Mikhail D. Lukin A1 - David A. B. Miller A1 - Christopher Monroe A1 - Sae Woo Nam A1 - Prineha Narang A1 - Jason S. Orcutt AB -

Just as classical information technology rests on a foundation built of interconnected information-processing systems, quantum information technology (QIT) must do the same. A critical component of such systems is the interconnect, a device or process that allows transfer of information between disparate physical media, for example, semiconductor electronics, individual atoms, light pulses in optical fiber, or microwave fields. While interconnects have been well engineered for decades in the realm of classical information technology, quantum interconnects (QuICs) present special challenges, as they must allow the transfer of fragile quantum states between different physical parts or degrees of freedom of the system. The diversity of QIT platforms (superconducting, atomic, solid-state color center, optical, etc.) that will form a quantum internet poses additional challenges. As quantum systems scale to larger size, the quantum interconnect bottleneck is imminent, and is emerging as a grand challenge for QIT. For these reasons, it is the position of the community represented by participants of the NSF workshop on Quantum Interconnects that accelerating QuIC research is crucial for sustained development of a national quantum science and technology program. Given the diversity of QIT platforms, materials used, applications, and infrastructure required, a convergent research program including partnership between academia, industry and national laboratories is required. This document is a summary from a U.S. National Science Foundation supported workshop held on 31 October - 1 November 2019 in Alexandria, VA. Attendees were charged to identify the scientific and community needs, opportunities, and significant challenges for quantum interconnects over the next 2-5 years. 

UR - https://arxiv.org/abs/1912.06642 ER - TY - JOUR T1 - Photon pair condensation by engineered dissipation JF - Phys. Rev. Lett. Y1 - 2019 A1 - Ze-Pei Cian A1 - Guanyu Zhu A1 - Su-Kuan Chu A1 - Alireza Seif A1 - Wade DeGottardi A1 - Liang Jiang A1 - Mohammad Hafezi AB -

Dissipation can usually induce detrimental decoherence in a quantum system. However, engineered dissipation can be used to prepare and stabilize coherent quantum many-body states. Here, we show that by engineering dissipators containing photon pair operators, one can stabilize an exotic dark state, which is a condensate of photon pairs with a phase-nematic order. In this system, the usual superfluid order parameter, i.e. single-photon correlation, is absent, while the photon pair correlation exhibits long-range order. Although the dark state is not unique due to multiple parity sectors, we devise an additional type of dissipators to stabilize the dark state in a particular parity sector via a diffusive annihilation process which obeys Glauber dynamics in an Ising model. Furthermore, we propose an implementation of these photon-pair dissipators in circuit-QED architecture. 

VL - 123 UR - https://arxiv.org/abs/1904.00016 CP - 063602 U5 - 10.1103/PhysRevLett.123.063602 ER - TY - JOUR T1 - Quantum repeaters based on two species trapped ions JF - New J. Phys. Y1 - 2019 A1 - Siddhartha Santra A1 - Sreraman Muralidharan A1 - Martin Lichtman A1 - Liang Jiang A1 - Christopher Monroe A1 - Vladimir S. Malinovsky AB -

We examine the viability of quantum repeaters based on two-species trapped ion modules for long distance quantum key distribution. Repeater nodes comprised of ion-trap modules of co-trapped ions of distinct species are considered. The species used for communication qubits has excellent optical properties while the other longer lived species serves as a memory qubit in the modules. Each module interacts with the network only via single photons emitted by the communication ions. Coherent Coulomb interaction between ions is utilized to transfer quantum information between the communication and memory ions and to achieve entanglement swapping between two memory ions. We describe simple modular quantum repeater architectures realizable with the ion-trap modules and numerically study the dependence of the quantum key distribution rate on various experimental parameters, including coupling efficiency, gate infidelity, operation time and length of the elementary links. Our analysis suggests crucial improvements necessary in a physical implementation for co-trapped two-species ions to be a competitive platform in long-distance quantum communication. 

VL - 21 UR - https://arxiv.org/abs/1811.10723 CP - 073002 U5 - https://doi.org/10.1088/1367-2630/ab2a45 ER - TY - JOUR T1 - Quantum Logic between Remote Quantum Registers JF - Physical Review A Y1 - 2013 A1 - Norman Y. Yao A1 - Zhe-Xuan Gong A1 - Chris R. Laumann A1 - Steven D. Bennett A1 - L. -M. Duan A1 - Mikhail D. Lukin A1 - Liang Jiang A1 - Alexey V. Gorshkov AB - We analyze two approaches to quantum state transfer in solid-state spin systems. First, we consider unpolarized spin-chains and extend previous analysis to various experimentally relevant imperfections, including quenched disorder, dynamical decoherence, and uncompensated long range coupling. In finite-length chains, the interplay between disorder-induced localization and decoherence yields a natural optimal channel fidelity, which we calculate. Long-range dipolar couplings induce a finite intrinsic lifetime for the mediating eigenmode; extensive numerical simulations of dipolar chains of lengths up to L=12 show remarkably high fidelity despite these decay processes. We further consider the extension of the protocol to bosonic systems of coupled oscillators. Second, we introduce a quantum mirror based architecture for universal quantum computing which exploits all of the spins in the system as potential qubits. While this dramatically increases the number of qubits available, the composite operations required to manipulate "dark" spin qubits significantly raise the error threshold for robust operation. Finally, as an example, we demonstrate that eigenmode-mediated state transfer can enable robust long-range logic between spatially separated Nitrogen-Vacancy registers in diamond; numerical simulations confirm that high fidelity gates are achievable even in the presence of moderate disorder. VL - 87 UR - http://arxiv.org/abs/1206.0014v1 CP - 2 J1 - Phys. Rev. A U5 - 10.1103/PhysRevA.87.022306 ER - TY - JOUR T1 - Topologically Protected Quantum State Transfer in a Chiral Spin Liquid JF - Nature Communications Y1 - 2013 A1 - Norman Y. Yao A1 - Chris R. Laumann A1 - Alexey V. Gorshkov A1 - Hendrik Weimer A1 - Liang Jiang A1 - J. Ignacio Cirac A1 - Peter Zoller A1 - Mikhail D. Lukin AB - Topology plays a central role in ensuring the robustness of a wide variety of physical phenomena. Notable examples range from the robust current carrying edge states associated with the quantum Hall and the quantum spin Hall effects to proposals involving topologically protected quantum memory and quantum logic operations. Here, we propose and analyze a topologically protected channel for the transfer of quantum states between remote quantum nodes. In our approach, state transfer is mediated by the edge mode of a chiral spin liquid. We demonstrate that the proposed method is intrinsically robust to realistic imperfections associated with disorder and decoherence. Possible experimental implementations and applications to the detection and characterization of spin liquid phases are discussed. VL - 4 U4 - 1585 UR - http://arxiv.org/abs/1110.3788v1 J1 - Nat Comms U5 - 10.1038/ncomms2531 ER - TY - JOUR T1 - Scalable Architecture for a Room Temperature Solid-State Quantum Information Processor JF - Nature Communications Y1 - 2012 A1 - Norman Y. Yao A1 - Liang Jiang A1 - Alexey V. Gorshkov A1 - Peter C. Maurer A1 - Geza Giedke A1 - J. Ignacio Cirac A1 - Mikhail D. Lukin AB - The realization of a scalable quantum information processor has emerged over the past decade as one of the central challenges at the interface of fundamental science and engineering. Much progress has been made towards this goal. Indeed, quantum operations have been demonstrated on several trapped ion qubits, and other solid-state systems are approaching similar levels of control. Extending these techniques to achieve fault-tolerant operations in larger systems with more qubits remains an extremely challenging goal, in part, due to the substantial technical complexity of current implementations. Here, we propose and analyze an architecture for a scalable, solid-state quantum information processor capable of operating at or near room temperature. The architecture is applicable to realistic conditions, which include disorder and relevant decoherence mechanisms, and includes a hierarchy of control at successive length scales. Our approach is based upon recent experimental advances involving Nitrogen-Vacancy color centers in diamond and will provide fundamental insights into the physics of non-equilibrium many-body quantum systems. Additionally, the proposed architecture may greatly alleviate the stringent constraints, currently limiting the realization of scalable quantum processors. VL - 3 U4 - 800 UR - http://arxiv.org/abs/1012.2864v1 J1 - Nat Comms U5 - 10.1038/ncomms1788 ER - TY - JOUR T1 - Robust Quantum State Transfer in Random Unpolarized Spin Chains JF - Physical Review Letters Y1 - 2011 A1 - Norman Y. Yao A1 - Liang Jiang A1 - Alexey V. Gorshkov A1 - Zhe-Xuan Gong A1 - Alex Zhai A1 - L. -M. Duan A1 - Mikhail D. Lukin AB - We propose and analyze a new approach for quantum state transfer between remote spin qubits. Specifically, we demonstrate that coherent quantum coupling between remote qubits can be achieved via certain classes of random, unpolarized (infinite temperature) spin chains. Our method is robust to coupling strength disorder and does not require manipulation or control over individual spins. In principle, it can be used to attain perfect state transfer over arbitrarily long range via purely Hamiltonian evolution and may be particularly applicable in a solid-state quantum information processor. As an example, we demonstrate that it can be used to attain strong coherent coupling between Nitrogen-Vacancy centers separated by micrometer distances at room temperature. Realistic imperfections and decoherence effects are analyzed. VL - 106 UR - http://arxiv.org/abs/1011.2762v2 CP - 4 J1 - Phys. Rev. Lett. U5 - 10.1103/PhysRevLett.106.040505 ER - TY - JOUR T1 - Fast Entanglement Distribution with Atomic Ensembles and Fluorescent Detection JF - Physical Review A Y1 - 2010 A1 - Jonatan B. Brask A1 - Liang Jiang A1 - Alexey V. Gorshkov A1 - Vladan Vuletic A1 - Anders S. Sorensen A1 - Mikhail D. Lukin AB - Quantum repeaters based on atomic ensemble quantum memories are promising candidates for achieving scalable distribution of entanglement over long distances. Recently, important experimental progress has been made towards their implementation. However, the entanglement rates and scalability of current approaches are limited by relatively low retrieval and single-photon detector efficiencies. We propose a scheme, which makes use of fluorescent detection of stored excitations to significantly increase the efficiency of connection and hence the rate. Practical performance and possible experimental realizations of the new protocol are discussed. VL - 81 UR - http://arxiv.org/abs/0907.3839v2 CP - 2 J1 - Phys. Rev. A U5 - 10.1103/PhysRevA.81.020303 ER - TY - JOUR T1 - Anyonic interferometry and protected memories in atomic spin lattices JF - Nature Physics Y1 - 2008 A1 - Liang Jiang A1 - Gavin K. Brennen A1 - Alexey V. Gorshkov A1 - Klemens Hammerer A1 - Mohammad Hafezi A1 - Eugene Demler A1 - Mikhail D. Lukin A1 - Peter Zoller AB - Strongly correlated quantum systems can exhibit exotic behavior called topological order which is characterized by non-local correlations that depend on the system topology. Such systems can exhibit remarkable phenomena such as quasi-particles with anyonic statistics and have been proposed as candidates for naturally fault-tolerant quantum computation. Despite these remarkable properties, anyons have never been observed in nature directly. Here we describe how to unambiguously detect and characterize such states in recently proposed spin lattice realizations using ultra-cold atoms or molecules trapped in an optical lattice. We propose an experimentally feasible technique to access non-local degrees of freedom by performing global operations on trapped spins mediated by an optical cavity mode. We show how to reliably read and write topologically protected quantum memory using an atomic or photonic qubit. Furthermore, our technique can be used to probe statistics and dynamics of anyonic excitations. VL - 4 U4 - 482 - 488 UR - http://arxiv.org/abs/0711.1365v1 CP - 6 J1 - Nat Phys U5 - 10.1038/nphys943 ER - TY - JOUR T1 - Coherence of an optically illuminated single nuclear spin qubit JF - Physical Review Letters Y1 - 2008 A1 - Liang Jiang A1 - M. V. Gurudev Dutt A1 - Emre Togan A1 - Lily Childress A1 - Paola Cappellaro A1 - J. M. Taylor A1 - Mikhail D. Lukin AB - We investigate the coherence properties of individual nuclear spin quantum bits in diamond [Dutt et al., Science, 316, 1312 (2007)] when a proximal electronic spin associated with a nitrogen-vacancy (NV) center is being interrogated by optical radiation. The resulting nuclear spin dynamics are governed by time-dependent hyperfine interaction associated with rapid electronic transitions, which can be described by a spin-fluctuator model. We show that due to a process analogous to motional averaging in nuclear magnetic resonance, the nuclear spin coherence can be preserved after a large number of optical excitation cycles. Our theoretical analysis is in good agreement with experimental results. It indicates a novel approach that could potentially isolate the nuclear spin system completely from the electronic environment. VL - 100 UR - http://arxiv.org/abs/0707.1341v2 CP - 7 J1 - Phys. Rev. Lett. U5 - 10.1103/PhysRevLett.100.073001 ER - TY - JOUR T1 - Coherent Quantum Optical Control with Subwavelength Resolution JF - Physical Review Letters Y1 - 2008 A1 - Alexey V. Gorshkov A1 - Liang Jiang A1 - Markus Greiner A1 - Peter Zoller A1 - Mikhail D. Lukin AB - We suggest a new method for quantum optical control with nanoscale resolution. Our method allows for coherent far-field manipulation of individual quantum systems with spatial selectivity that is not limited by the wavelength of radiation and can, in principle, approach a few nanometers. The selectivity is enabled by the nonlinear atomic response, under the conditions of Electromagnetically Induced Transparency, to a control beam with intensity vanishing at a certain location. Practical performance of this technique and its potential applications to quantum information science with cold atoms, ions, and solid-state qubits are discussed. VL - 100 UR - http://arxiv.org/abs/0706.3879v2 CP - 9 J1 - Phys. Rev. Lett. U5 - 10.1103/PhysRevLett.100.093005 ER -