PRA: Quantum information

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Recently published articles in Phys. Rev. A in the Table of Content section "Quantum information"
Updated: 41 min 47 sec ago

Unification of quantum resources in distributed scenarios

Fri, 2019-02-22 11:00

Author(s): Hongyi Zhou, Xiao Yuan, and Xiongfeng Ma

Quantum resources, such as coherence, discord, and entanglement, play a key role for demonstrating an advantage in many computation and communication tasks. In order to find the nature behind these resources, tremendous efforts have been made to explore the connections between them. In this work, we...


[Phys. Rev. A 99, 022326] Published Fri Feb 22, 2019

Categories: Journals, Physics

Adiabatic quantum simulations with driven superconducting qubits

Thu, 2019-02-21 11:00

Author(s): Marco Roth, Nikolaj Moll, Gian Salis, Marc Ganzhorn, Daniel J. Egger, Stefan Filipp, and Sebastian Schmidt

We propose a quantum simulator based on driven superconducting qubits where the interactions are generated parametrically by a bichromatic magnetic flux modulation of a tunable bus element. Using a time-dependent Schrieffer-Wolff transformation, we analytically derive a multiqubit Hamiltonian which ...


[Phys. Rev. A 99, 022323] Published Thu Feb 21, 2019

Categories: Journals, Physics

Sensitivity bounds for interferometry with Ising Hamiltonians

Thu, 2019-02-21 11:00

Author(s): Yan Li, Luca Pezzè, Weidong Li, and Augusto Smerzi

Sensitivity bounds for a generic interferometric phase estimation problem are the shot noise and the Heisenberg limits. The shot noise is the highest sensitivity that can be reached with separable states, while the Heisenberg limit is the ultimate bound in sensitivity which can be saturated with ent...


[Phys. Rev. A 99, 022324] Published Thu Feb 21, 2019

Categories: Journals, Physics

Quantum remote sensing with asymmetric information gain

Thu, 2019-02-21 11:00

Author(s): Yuki Takeuchi, Yuichiro Matsuzaki, Koichiro Miyanishi, Takanori Sugiyama, and William J. Munro

Typically, the aim of quantum metrology is to sense target fields with high precision utilizing quantum properties. Unlike the typical aim, in this paper, we use quantum properties for adding a functionality to quantum sensors. More concretely, we propose a delegated quantum sensor (a client-server ...


[Phys. Rev. A 99, 022325] Published Thu Feb 21, 2019

Categories: Journals, Physics

Relativistic chiral qubits, their time evolution, and correlations

Wed, 2019-02-20 11:00

Author(s): Jakub Rembieliński and Paweł Caban

We introduce and discuss the concept of chiral relativistic qubit as an irreducible amount of quantum information related to a one-half spin relativistic chiral elementary system (carrier particle). We propose a Lorentz-covariant time evolution of the qubit which on the level of the density matrix i...


[Phys. Rev. A 99, 022320] Published Wed Feb 20, 2019

Categories: Journals, Physics

Measure of positive and not completely positive single-qubit Pauli maps

Wed, 2019-02-20 11:00

Author(s): Vinayak Jagadish, R. Srikanth, and Francesco Petruccione

The time evolution of an initially uncorrelated system is governed by a completely positive (CP) map. More generally, the system may contain initial (quantum) correlations with an environment, in which case the system evolves according to a not-completely positive (NCP) map. It is an interesting que...


[Phys. Rev. A 99, 022321] Published Wed Feb 20, 2019

Categories: Journals, Physics

Long-distance continuous-variable measurement-device-independent quantum key distribution with discrete modulation

Wed, 2019-02-20 11:00

Author(s): Hong-Xin Ma, Peng Huang, Dong-Yun Bai, Tao Wang, Shi-Yu Wang, Wan-Su Bao, and Gui-Hua Zeng

We propose a long-distance continuous-variable measurement-device-independent quantum key distribution (CV-MDI-QKD) protocol with discrete modulation. This kind of discrete-modulated scheme has good compatibility with efficient error correction code, which leads to higher reconciliation efficiency e...


[Phys. Rev. A 99, 022322] Published Wed Feb 20, 2019

Categories: Journals, Physics

Universal quantum gates between nitrogen-vacancy centers in a levitated nanodiamond

Tue, 2019-02-19 11:00

Author(s): Xing-Yan Chen and Zhang-qi Yin

We propose a scheme to realize the controlled-phase gates between nitrogen-vacancy (NV) centers in an optically trapped nanodiamond, through a uniform magnetic field-induced coupling between the NV centers and the torsional mode of the levitated nanodiamond. The gates are insensitive to the thermal ...


[Phys. Rev. A 99, 022319] Published Tue Feb 19, 2019

Categories: Journals, Physics

Unbounded sequence of observers exhibiting Einstein-Podolsky-Rosen steering

Fri, 2019-02-15 11:00

Author(s): Akshata Shenoy H., Sébastien Designolle, Flavien Hirsch, Ralph Silva, Nicolas Gisin, and Nicolas Brunner

A sequential steering scenario is investigated, where multiple Bobs aim at demonstrating steering using successively the same half of an entangled quantum state. With isotropic entangled states of local dimension d, the number of Bobs that can steer Alice is found to be NBob∼d/logd, thus leading to ...


[Phys. Rev. A 99, 022317] Published Fri Feb 15, 2019

Categories: Journals, Physics

Carrier-phase estimation for simultaneous quantum key distribution and classical communication using a real local oscillator

Fri, 2019-02-15 11:00

Author(s): Tao Wang, Peng Huang, Shiyu Wang, and Guihua Zeng

The simultaneous quantum and classical communication (SQCC) protocol is an appealing protocol since it allows continuous-variable quantum key distribution (CV-QKD) and classical communication to be implemented simultaneously by using the same communication infrastructure and on a single wavelength. ...


[Phys. Rev. A 99, 022318] Published Fri Feb 15, 2019

Categories: Journals, Physics

Cryptographic quantum metrology

Wed, 2019-02-13 11:00

Author(s): Zixin Huang, Chiara Macchiavello, and Lorenzo Maccone

We develop a general framework for parameter estimation that allows only trusted parties to access the result and achieves optimal precision. The protocols are designed such that adversaries can access some information indeterministically, but only at the risk of getting caught (cheat sensitivity); ...


[Phys. Rev. A 99, 022314] Published Wed Feb 13, 2019

Categories: Journals, Physics

Asymmetric broadcasting of quantum correlations

Wed, 2019-02-13 11:00

Author(s): Aditya Jain, Indranil Chakrabarty, and Sourav Chatterjee

In this work, we exhaustively investigate 1→2 local and nonlocal broadcasting of entanglement as well as correlations beyond entanglement (geometric discord) using asymmetric Pauli cloners with the most general two-qubit state as the resource. We exemplify asymmetric broadcasting of entanglement usi...


[Phys. Rev. A 99, 022315] Published Wed Feb 13, 2019

Categories: Journals, Physics

Local unambiguous discrimination of symmetric ternary states

Wed, 2019-02-13 11:00

Author(s): Kenji Nakahira, Kentaro Kato, and Tsuyoshi Sasaki Usuda

We investigate unambiguous discrimination between given quantum states with a sequential measurement, which is restricted to local measurements and one-way classical communication. If the given states are binary or each of their individual state spaces is two dimensional, then it is in some cases kn...


[Phys. Rev. A 99, 022316] Published Wed Feb 13, 2019

Categories: Journals, Physics

Proof of efficient, parallelized, universal adiabatic quantum computation

Tue, 2019-02-12 11:00

Author(s): Ari Mizel

We give a careful proof that a parallelized version of adiabatic quantum computation can efficiently simulate universal gate model quantum computation. The proof specifies an explicit parameter-dependent Hamiltonian H(λ) that is based on ground state quantum computation [Mizel et al., Phys. Rev. A....


[Phys. Rev. A 99, 022311] Published Tue Feb 12, 2019

Categories: Journals, Physics

Overcomplete quantum tomography of a path-entangled two-photon state

Tue, 2019-02-12 11:00

Author(s): L. De Santis, G. Coppola, C. Antón, N. Somaschi, C. Gómez, A. Lemaître, I. Sagnes, L. Lanco, J. C. Loredo, O. Krebs, and P. Senellart

Path-entangled N-photon states are key resources for quantum enhanced metrology and quantum imaging, as well as quantum computation. However, the quantum tomography of path-entangled indistinguishable photons is still in its infancy. We propose and implement a quantum tomographical method to charact...


[Phys. Rev. A 99, 022312] Published Tue Feb 12, 2019

Categories: Journals, Physics

Performance of quantum error correction with coherent errors

Tue, 2019-02-12 11:00

Author(s): Eric Huang, Andrew C. Doherty, and Steven Flammia

We compare the performance of quantum error correcting codes when memory errors are unitary with the more familiar case of dephasing noise. For a wide range of codes, we analytically compute the effective logical channel that results when the error correction steps are performed noiselessly. Our exa...


[Phys. Rev. A 99, 022313] Published Tue Feb 12, 2019

Categories: Journals, Physics

Entanglement negativity of fermions: Monotonicity, separability criterion, and classification of few-mode states

Mon, 2019-02-11 11:00

Author(s): Hassan Shapourian and Shinsei Ryu

We study quantum information aspects of the fermionic entanglement negativity recently introduced [H. Shapourian et al., Phys. Rev. B 95, 165101 (2017)] based on the fermionic partial transpose. In particular, we show that it is an entanglement monotone under the action of local quantum operations ...


[Phys. Rev. A 99, 022310] Published Mon Feb 11, 2019

Categories: Journals, Physics

One-way local distinguishability of generalized Bell states in arbitrary dimension

Fri, 2019-02-08 11:00

Author(s): Yan-Ling Wang, Mao-Sheng Li, and Zong-Xing Xiong

In this paper, we study the distinguishability of arbitrary dimensional generalized Bell states under one-way local operations and classical communication (LOCC). We introduce an admissible solutions set and a nonadmissible solutions set for each set of generalized Bell states. Any element that exis...


[Phys. Rev. A 99, 022307] Published Fri Feb 08, 2019

Categories: Journals, Physics

Quantum codes for quantum simulation of fermions on a square lattice of qubits

Fri, 2019-02-08 11:00

Author(s): Mark Steudtner and Stephanie Wehner

Quantum simulation of fermionic systems is a promising application of quantum computers, but to program them, we need to map fermionic states and operators to qubit states and quantum gates. While quantum processors may be built as two-dimensional qubit networks with couplings between nearest neighb...


[Phys. Rev. A 99, 022308] Published Fri Feb 08, 2019

Categories: Journals, Physics

Necessary and sufficient condition of separability for $\mathrm{D}$-symmetric diagonal states

Fri, 2019-02-08 11:00

Author(s): A. Rutkowski, M. Banacki, and M. Marciniak

For multipartite states, we consider a notion of D symmetry. For a system of N qubits, it coincides with the usual permutational symmetry. In the case of N qudits (d≥3), the D symmetry is stronger than the permutational one. For the space of all D-symmetric vectors in (Cd)⊗N, we define a basis compo...


[Phys. Rev. A 99, 022309] Published Fri Feb 08, 2019

Categories: Journals, Physics