Long-Term Behaviour in an Exactly Solvable Model of Pure Decoherence and the Problem of Markovian Embedding

We consider a well-known, exactly solvable model of an open quantum system with pure decoherence. The aim of this paper is twofold. Firstly, decoherence is a property of open quantum systems important for both quantum technologies and the fundamental question of the quantum–classical transition. It...

Full description

Bibliographic Details
Main Author: Anton Trushechkin
Format: Article
Language:English
Published: MDPI AG 2023-12-01
Series:Mathematics
Subjects:
Online Access:https://www.mdpi.com/2227-7390/12/1/1
_version_ 1827384689347788800
author Anton Trushechkin
author_facet Anton Trushechkin
author_sort Anton Trushechkin
collection DOAJ
description We consider a well-known, exactly solvable model of an open quantum system with pure decoherence. The aim of this paper is twofold. Firstly, decoherence is a property of open quantum systems important for both quantum technologies and the fundamental question of the quantum–classical transition. It is worth studying how the long-term rate of decoherence depends on the spectral density characterising the system–bath interaction in this exactly solvable model. Secondly, we address a more general problem of the Markovian embedding of non-Markovian open system dynamics. It is often assumed that a non-Markovian open quantum system can be embedded into a larger Markovian system. However, we show that such embedding is possible only for Ohmic spectral densities (for the case of a positive bath temperature) and is impossible for both sub- and super-Ohmic spectral densities. On the other hand, for Ohmic spectral densities, an asymptotic large-time Markovianity (in terms of the quantum regression formula) takes place.
first_indexed 2024-03-08T15:01:59Z
format Article
id doaj.art-003313150a82466a89a7c3972f322c1a
institution Directory Open Access Journal
issn 2227-7390
language English
last_indexed 2024-03-08T15:01:59Z
publishDate 2023-12-01
publisher MDPI AG
record_format Article
series Mathematics
spelling doaj.art-003313150a82466a89a7c3972f322c1a2024-01-10T15:03:15ZengMDPI AGMathematics2227-73902023-12-01121110.3390/math12010001Long-Term Behaviour in an Exactly Solvable Model of Pure Decoherence and the Problem of Markovian EmbeddingAnton Trushechkin0Department of Mathematical Physics, Steklov Mathematical Institute of Russian Academy of Sciences, Gubkina 8, Moscow 119991, RussiaWe consider a well-known, exactly solvable model of an open quantum system with pure decoherence. The aim of this paper is twofold. Firstly, decoherence is a property of open quantum systems important for both quantum technologies and the fundamental question of the quantum–classical transition. It is worth studying how the long-term rate of decoherence depends on the spectral density characterising the system–bath interaction in this exactly solvable model. Secondly, we address a more general problem of the Markovian embedding of non-Markovian open system dynamics. It is often assumed that a non-Markovian open quantum system can be embedded into a larger Markovian system. However, we show that such embedding is possible only for Ohmic spectral densities (for the case of a positive bath temperature) and is impossible for both sub- and super-Ohmic spectral densities. On the other hand, for Ohmic spectral densities, an asymptotic large-time Markovianity (in terms of the quantum regression formula) takes place.https://www.mdpi.com/2227-7390/12/1/1open quantum systemsdecoherenceMarkovian dynamicsnon-Markovian dynamics
spellingShingle Anton Trushechkin
Long-Term Behaviour in an Exactly Solvable Model of Pure Decoherence and the Problem of Markovian Embedding
Mathematics
open quantum systems
decoherence
Markovian dynamics
non-Markovian dynamics
title Long-Term Behaviour in an Exactly Solvable Model of Pure Decoherence and the Problem of Markovian Embedding
title_full Long-Term Behaviour in an Exactly Solvable Model of Pure Decoherence and the Problem of Markovian Embedding
title_fullStr Long-Term Behaviour in an Exactly Solvable Model of Pure Decoherence and the Problem of Markovian Embedding
title_full_unstemmed Long-Term Behaviour in an Exactly Solvable Model of Pure Decoherence and the Problem of Markovian Embedding
title_short Long-Term Behaviour in an Exactly Solvable Model of Pure Decoherence and the Problem of Markovian Embedding
title_sort long term behaviour in an exactly solvable model of pure decoherence and the problem of markovian embedding
topic open quantum systems
decoherence
Markovian dynamics
non-Markovian dynamics
url https://www.mdpi.com/2227-7390/12/1/1
work_keys_str_mv AT antontrushechkin longtermbehaviourinanexactlysolvablemodelofpuredecoherenceandtheproblemofmarkovianembedding