Enhancing quantum state discrimination with indefinite causal order

The standard quantum state discrimination problem can be understood as a communication scenario involving a sender and a receiver following these three steps: (i) the sender encodes information in pre-agreed quantum states, (ii) sends them over a noiseless channel, and (iii) the receiver decodes the...

Full description

Saved in:
Bibliographic Details
Main Authors: Spiros Kechrimparis, James Moran, Athena Karsa, Changhyoup Lee, Hyukjoon Kwon
Format: Article
Language:English
Published: IOP Publishing 2024-01-01
Series:New Journal of Physics
Subjects:
Online Access:https://doi.org/10.1088/1367-2630/ada05e
Tags: Add Tag
No Tags, Be the first to tag this record!
_version_ 1846100443838545920
author Spiros Kechrimparis
James Moran
Athena Karsa
Changhyoup Lee
Hyukjoon Kwon
author_facet Spiros Kechrimparis
James Moran
Athena Karsa
Changhyoup Lee
Hyukjoon Kwon
author_sort Spiros Kechrimparis
collection DOAJ
description The standard quantum state discrimination problem can be understood as a communication scenario involving a sender and a receiver following these three steps: (i) the sender encodes information in pre-agreed quantum states, (ii) sends them over a noiseless channel, and (iii) the receiver decodes the information by performing appropriate measurements on the received states. In a practical setting, however, the channel is not only noisy but often also unknown, thus altering the states and making optimal decoding generally not possible. In this work, we study this noisy discrimination scenario using a protocol based on indefinite causal order. To this end, we consider the quantum switch and define its higher-order generalisations, which we call superswitches . We find that, for certain channels and ensembles, the guessing probability can be significantly improved compared to both single- and multiple-copy state discrimination.
format Article
id doaj-art-568921d618ea4df0a2bf9b5ae5f55df7
institution Kabale University
issn 1367-2630
language English
publishDate 2024-01-01
publisher IOP Publishing
record_format Article
series New Journal of Physics
spelling doaj-art-568921d618ea4df0a2bf9b5ae5f55df72024-12-30T08:00:35ZengIOP PublishingNew Journal of Physics1367-26302024-01-01261212303010.1088/1367-2630/ada05eEnhancing quantum state discrimination with indefinite causal orderSpiros Kechrimparis0https://orcid.org/0000-0002-8731-9334James Moran1Athena Karsa2Changhyoup Lee3https://orcid.org/0000-0002-1401-4230Hyukjoon Kwon4https://orcid.org/0000-0001-5520-0905School of Computational Sciences, Korea Institute for Advanced Study , Seoul 02455, Republic of KoreaQuantum Universe Center, Korea Institute for Advanced Study , Seoul 02455, Republic of KoreaSchool of Physics & Astronomy, University College London , London WC1E 6BT, United Kingdom; Korea Research Institute of Standards and Science , Daejeon 34113, Republic of KoreaKorea Research Institute of Standards and Science , Daejeon 34113, Republic of KoreaSchool of Computational Sciences, Korea Institute for Advanced Study , Seoul 02455, Republic of Korea; Quantum Universe Center, Korea Institute for Advanced Study , Seoul 02455, Republic of KoreaThe standard quantum state discrimination problem can be understood as a communication scenario involving a sender and a receiver following these three steps: (i) the sender encodes information in pre-agreed quantum states, (ii) sends them over a noiseless channel, and (iii) the receiver decodes the information by performing appropriate measurements on the received states. In a practical setting, however, the channel is not only noisy but often also unknown, thus altering the states and making optimal decoding generally not possible. In this work, we study this noisy discrimination scenario using a protocol based on indefinite causal order. To this end, we consider the quantum switch and define its higher-order generalisations, which we call superswitches . We find that, for certain channels and ensembles, the guessing probability can be significantly improved compared to both single- and multiple-copy state discrimination.https://doi.org/10.1088/1367-2630/ada05equantum state discriminationindefinite causal orderquantum communicationquantum switch
spellingShingle Spiros Kechrimparis
James Moran
Athena Karsa
Changhyoup Lee
Hyukjoon Kwon
Enhancing quantum state discrimination with indefinite causal order
New Journal of Physics
quantum state discrimination
indefinite causal order
quantum communication
quantum switch
title Enhancing quantum state discrimination with indefinite causal order
title_full Enhancing quantum state discrimination with indefinite causal order
title_fullStr Enhancing quantum state discrimination with indefinite causal order
title_full_unstemmed Enhancing quantum state discrimination with indefinite causal order
title_short Enhancing quantum state discrimination with indefinite causal order
title_sort enhancing quantum state discrimination with indefinite causal order
topic quantum state discrimination
indefinite causal order
quantum communication
quantum switch
url https://doi.org/10.1088/1367-2630/ada05e
work_keys_str_mv AT spiroskechrimparis enhancingquantumstatediscriminationwithindefinitecausalorder
AT jamesmoran enhancingquantumstatediscriminationwithindefinitecausalorder
AT athenakarsa enhancingquantumstatediscriminationwithindefinitecausalorder
AT changhyouplee enhancingquantumstatediscriminationwithindefinitecausalorder
AT hyukjoonkwon enhancingquantumstatediscriminationwithindefinitecausalorder