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Papers

Live trends in quantum computing research, updated daily from arXiv.

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15,849 papers in 12 months (-35% vs prior quarter)

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31,937 papers found

Observing a quantum Maxwell demon at work

N. Cottet, S. Jezouin, L. Bretheau +7 more·Feb 16, 2017

Significance Maxwell’s demon plays a central role in thermodynamics of quantum information, yet a full experimental characterization is still missing in the quantum regime. Here we use superconducting circuits to realize a quantum Maxwell demon in wh...

PhysicsMedicineMathematics

Logical Randomized Benchmarking

J. Combes, C. Granade, C. Ferrie +1 more·Feb 13, 2017

Extrapolating physical error rates to logical error rates requires many assumptions and thus can radically under- or overestimate the performance of an error correction implementation. We introduce logical randomized benchmarking, a characterization ...

MathematicsPhysics

Dirac bi-spinor entanglement under local noise and its simulation by Jaynes-Cummings interactions

V. Bittencourt, A. Bernardini·Feb 13, 2017

A description of the effects of the local noise on the quantum entanglement constraining the internal degrees of freedom of Dirac bi-spinor structures driven by arbitrary Poincaré invariant potentials is proposed. Given that the Dirac equation dynami...

PhysicsMathematics

Post-Quantum Cryptography(PQC): Generalized ElGamal Cipher over GL(8,F251)

P. Hecht·Feb 12, 2017

Post-quantum cryptography (PQC) attempts to find cryptographic protocols resistant to attacks using for instance Shor's polynomial time algorithm for numerical field problems like integer factorization (IFP) or the discrete logarithm (DLP). Other asp...

Computer Science

Coherence number as a discrete quantum resource

Seungbeom Chin·Feb 10, 2017

We introduce a new discrete coherence monotone named the \emph{coherence number}, which is a generalization of the coherence rank to mixed states. After defining the coherence number in a similar manner to the Schmidt number in entanglement theory, w...

PhysicsComputer ScienceMathematics

Near-optimal quantum circuit for Grover's unstructured search using a transverse field

Zhang Jiang, E. Rieffel, Zhihui Wang·Feb 8, 2017

Inspired by a class of algorithms proposed by Farhi et al. (arXiv:1411.4028), namely the quantum approximate optimization algorithm (QAOA), we present a circuit-based quantum algorithm to search for a needle in a haystack, obtaining the same quadrati...

Physics

A Quantum von Neumann Architecture for Large-Scale Quantum Computing in Systems with Long Coherence Times, such as Trapped Ions

M. F. Brandl·Feb 8, 2017

As the size of quantum systems becomes bigger, more complicated hardware is required to control these systems. In order to reduce the complexity, I discuss the amount of parallelism required for a fault-tolerant quantum computer and what computation ...

MathematicsPhysics

What Randomized Benchmarking Actually Measures.

T. Proctor, K. Rudinger, K. Young +2 more·Feb 7, 2017

Randomized benchmarking (RB) is widely used to measure an error rate of a set of quantum gates, by performing random circuits that would do nothing if the gates were perfect. In the limit of no finite-sampling error, the exponential decay rate of the...

MathematicsPhysicsMedicine

Experimental comparison of two quantum computing architectures

N. Linke, D. Maslov, M. Rötteler +5 more·Feb 7, 2017

Significance Quantum computers are an emerging technology promising to be vastly more powerful at solving certain problems than any conventional computer. These devices are now moving out of the laboratory and becoming generally programmable. This al...

Computer SciencePhysicsMedicine

Efficient detection of useful long-range entanglement in imperfect cluster states

T. Nutz, A. Milne, P. Shadbolt +1 more·Feb 7, 2017

Photonic cluster states are a crucial resource for optical quantum computing. Recently a quantum dot single photon source has been demonstrated to produce strings of photons in a linear cluster state, but high photon loss rates make it impossible to ...

Physics

Quantum Correlations in Nonlocal BosonSampling

F. Shahandeh, A. Lund, T. Ralph·Feb 7, 2017

Determination of the quantum nature of correlations between two spatially separated systems plays a crucial role in quantum information science. Of particular interest is the questions of if and how these correlations enable quantum information proto...

PhysicsComputer ScienceMedicineMathematics

A class of time-energy uncertainty relations for time-dependent Hamiltonians

T. Kieu·Feb 2, 2017

A new class of time-energy uncertainty relations is directly derived from the Schrödinger equations for time-dependent Hamiltonians. Only the initial states and the Hamiltonians, but neither the instantaneous eigenstates nor the full time-dependent w...

MathematicsPhysics

Quantum nonlinear optics without photons

R. Stassi, V. Macrì, A. F. Kockum +4 more·Feb 2, 2017

Spontaneous parametric down-conversion is a well-known process in quantum nonlinear optics in which a photon incident on a nonlinear crystal spontaneously splits into two photons. Here we propose an analogous physical process where one excited atom d...

PhysicsMathematics

Quantum algorithms for computing short discrete logarithms and factoring RSA integers

Martin Ekerå, J. Håstad·Feb 1, 2017

We generalize the quantum algorithm for computing short discrete logarithms previously introduced by Ekera [2] so as to allow for various tradeoffs between the number of times that the algorithm need be executed on the one hand, and the complexity of...

Computer ScienceMathematicsPhysics

Quantum jumps, superpositions, and the continuous evolution of quantum states

R. Dick·Feb 1, 2017

Abstract The apparent dichotomy between quantum jumps on the one hand, and continuous time evolution according to wave equations on the other hand, provided a challenge to Bohr's proposal of quantum jumps in atoms. Furthermore, Schrodinger's time-dep...

Physics

Schrödinger cat and Werner state disentanglement simulated by trapped ion systems

V. Bittencourt, A. Bernardini·Jan 30, 2017

Disentanglement and loss of quantum correlations due to one global collective noise effect are described for two-qubit Schrödinger cat and Werner states of a four level trapped ion quantum system. Once the Jaynes–Cummings ionic interactions are mappe...

Physics

Fully graphical treatment of the quantum algorithm for the Hidden Subgroup Problem

S. Gogioso, A. Kissinger·Jan 30, 2017

The abelian Hidden Subgroup Problem (HSP) is extremely general, and many problems with known quantum exponential speed-up (such as integers factorisation, the discrete logarithm and Simon's problem) can be seen as specific instances of it. The tradit...

Computer ScienceMathematicsPhysics

Quantum Monte Carlo annealing with multi-spin dynamics

G. Mazzola, M. Troyer·Jan 30, 2017

We introduce a novel simulated quantum annealing (SQA) algorithm which employs a multispin quantum fluctuation operator. At variance with the usual transverse field, short-range two-spin flip interactions are included in the driver Hamiltonian. A Qua...

MathematicsPhysics

Experimental protection of arbitrary states in a two-qubit subspace by nested Uhrig dynamical decoupling

Harpreet Singh, Arvind, K. Dorai·Jan 28, 2017

We experimentally demonstrate the efficacy of a three-layer nested Uhrig dynamical decoupling (NUDD) sequence to preserve arbitrary quantum states in a two-dimensional subspace of the four-dimensional two-qubit Hilbert space, on an NMR quantum inform...

Physics

Tapering off qubits to simulate fermionic Hamiltonians

S. Bravyi, J. Gambetta, Antonio Mezzacapo +1 more·Jan 27, 2017

We discuss encodings of fermionic many-body systems by qubits in the presence of symmetries. Such encodings eliminate redundant degrees of freedom in a way that preserves a simple structure of the system Hamiltonian enabling quantum simulations with ...

PhysicsMathematics
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