PhysRevA.96.022117.pdf (1.93 MB)

Simple procedure for phase-space measurement and entanglement validation

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journal contribution
posted on 24.08.2017, 08:06 by Russell Rundle, P.W. Mills, Todd Tilma, John Samson, Mark Everitt
It has recently been shown that it is possible to represent the complete quantum state of any system as a phase-space quasiprobability distribution (Wigner function) [Phys. Rev. Lett. 117, 180401 (2016)]. Such functions take the form of expectation values of an observable that has a direct analogy to displaced parity operators. In this work we give a procedure for the measurement of the Wigner function that should be applicable to any quantum system. We have applied our procedure to IBM's Quantum Experience five-qubit quantum processor to demonstrate that we can measure and generate the Wigner functions of two different Bell states as well as the five-qubit Greenberger–Horne–Zeilinger state. Because Wigner functions for spin systems are not unique, we define, compare, and contrast two distinct examples. We show how the use of these Wigner functions leads to an optimal method for quantum state analysis especially in the situation where specific characteristic features are of particular interest (such as for spin Schrödinger cat states). Furthermore we show that this analysis leads to straightforward, and potentially very efficient, entanglement test and state characterization methods.

Funding

R.P.Rundle is funded by the EPSRC [grant number EP/N509516/1].

History

School

  • Mechanical, Electrical and Manufacturing Engineering

Published in

Physical Review A

Volume

96

Citation

RUNDLE, R.P. ... et al, 2017. Simple procedure for phase-space measurement and entanglement validation. Physical Review A, 96, 022117.

Publisher

American Physical Society

Version

VoR (Version of Record)

Publisher statement

This work is made available according to the conditions of the Creative Commons Attribution 4.0 International (CC BY 4.0) licence. Full details of this licence are available at: http://creativecommons.org/licenses/by/4.0/

Acceptance date

29/06/2017

Publication date

2017

Notes

This paper was published by the American Physical Society under the terms of the Creative Commons Attribution 4.0 International license. Further distribution of this work must maintain attribution to the author(s) and the published article's title, journal citation, and DOI. Supplementary data for this article is available in Loughborough Data Repository at https://doi.org/10.17028/rd.lboro.c.3924277

ISSN

2469-9926

eISSN

2469-9934

Language

en

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