Projekteja vuodessa
Abstrakti
Correlations disguised in various forms underlie a host of important phenomena in classical and quantum systems, such as information and energy exchanges. The quantum mutual information and the norm of the correlation matrix are both considered as proper measures of total correlations. We demonstrate that, when applied to the same system, these two measures can actually show significantly different behavior except at least in two limiting cases: when there are no correlations and when there is maximal quantum entanglement. We further quantify the discrepancy by providing analytic formulas for time derivatives of the measures for an interacting bipartite system evolving unitarily. We argue that to properly account for correlations one should consider the full information provided by the correlation matrix (and reduced states of the subsystems). Scalar quantities such as the norm of the correlation matrix or the quantum mutual information can only capture a part of the complex features of correlations. As a concrete example, we show that in describing heat exchange associated with correlations neither of these quantities can fully capture the underlying physics. As a byproduct, we also prove an area law for quantum mutual information in systems with local and shortrange interactions, without need to assume Markovianity or final thermal equilibrium.
Alkuperäiskieli  Englanti 

Artikkeli  042311 
Sivut  16 
Sivumäärä  6 
Julkaisu  Physical Review A 
Vuosikerta  101 
Numero  4 
DOI  pysyväislinkit  
Tila  Julkaistu  7 huhtik. 2020 
OKMjulkaisutyyppi  A1 Julkaistu artikkeli, soviteltu 
Sormenjälki
Sukella tutkimusaiheisiin 'Unreliability of mutual information as a measure for variations in total correlations'. Ne muodostavat yhdessä ainutlaatuisen sormenjäljen.Projektit
 1 Päättynyt

Kvanttiteknologian huippuyksikkö
Alipour, S., AlaNissilä, T., Fan, Z., Tuorila, J. & Hirvonen, P.
01/01/2018 → 31/12/2020
Projekti: Academy of Finland: Other research funding