{"title":"On the Eternal Non-Markovianity of Non-Unital Quantum Channels","authors":"Shrikant Utagi, Subhashish Banerjee, R. Srikanth","doi":"10.1142/s0219749923500399","DOIUrl":null,"url":null,"abstract":"The eternally non-Markovian (ENM) Pauli channel is an example of a unital channel characterized by a negative decay rate for all time [Formula: see text]. Here, we consider the problem of constructing an analogous non-unital channel, and show in particular that a [Formula: see text]-dimensional generalized amplitude damping (GAD) channel cannot be ENM when the non-Markovianity originates solely from the non-unital part of the channel. We study specific ramifications of this result for qubit GAD. Specifically, we construct a quasi-ENM qubit GAD channel, characterized by a time [Formula: see text], such that the channel is non-Markovian (NM) only and for all time [Formula: see text]. We further point out that our negative result for the qudit GAD channel, namely, the impossibility of the eternal NM property, does not hold for a general qubit or higher-dimensional non-unital channel.","PeriodicalId":51058,"journal":{"name":"International Journal of Quantum Information","volume":null,"pages":null},"PeriodicalIF":0.7000,"publicationDate":"2023-11-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"2","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"International Journal of Quantum Information","FirstCategoryId":"1085","ListUrlMain":"https://doi.org/10.1142/s0219749923500399","RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q3","JCRName":"COMPUTER SCIENCE, THEORY & METHODS","Score":null,"Total":0}
引用次数: 2
Abstract
The eternally non-Markovian (ENM) Pauli channel is an example of a unital channel characterized by a negative decay rate for all time [Formula: see text]. Here, we consider the problem of constructing an analogous non-unital channel, and show in particular that a [Formula: see text]-dimensional generalized amplitude damping (GAD) channel cannot be ENM when the non-Markovianity originates solely from the non-unital part of the channel. We study specific ramifications of this result for qubit GAD. Specifically, we construct a quasi-ENM qubit GAD channel, characterized by a time [Formula: see text], such that the channel is non-Markovian (NM) only and for all time [Formula: see text]. We further point out that our negative result for the qudit GAD channel, namely, the impossibility of the eternal NM property, does not hold for a general qubit or higher-dimensional non-unital channel.
期刊介绍:
The International Journal of Quantum Information (IJQI) provides a forum for the interdisciplinary field of Quantum Information Science. In particular, we welcome contributions in these areas of experimental and theoretical research:
Quantum Cryptography
Quantum Computation
Quantum Communication
Fundamentals of Quantum Mechanics
Authors are welcome to submit quality research and review papers as well as short correspondences in both theoretical and experimental areas. Submitted articles will be refereed prior to acceptance for publication in the Journal.