Back to Search Start Over

Irreversibility and the arrow of time in a quenched quantum system

Authors :
Batalhao, T. B.
Souza, A. M.
Sarthour, R. S.
Oliveira, I. S.
Paternostro, M.
Lutz, E.
Serra, R. M.
Source :
Phys. Rev. Lett. 115, 190601 (2015)
Publication Year :
2015

Abstract

Irreversibility is one of the most intriguing concepts in physics. While microscopic physical laws are perfectly reversible, macroscopic average behavior has a preferred direction of time. According to the second law of thermodynamics, this arrow of time is associated with a positive mean entropy production. Using a nuclear magnetic resonance setup, we measure the nonequilibrium entropy produced in an isolated spin-1/2 system following fast quenches of an external magnetic field and experimentally demonstrate that it is equal to the entropic distance, expressed by the Kullback-Leibler divergence, between a microscopic process and its time-reverse. Our result addresses the concept of irreversibility from a microscopic quantum standpoint.<br />Comment: 8 pages, 7 figures, RevTeX4-1; Accepted for publication Phys. Rev. Lett

Details

Database :
arXiv
Journal :
Phys. Rev. Lett. 115, 190601 (2015)
Publication Type :
Report
Accession number :
edsarx.1502.06704
Document Type :
Working Paper
Full Text :
https://doi.org/10.1103/PhysRevLett.115.190601