7th KIAS Conference on Statistical Physics
[Talk 14] Irreversibility and the arrow of time in a quenched quantum
SPEAKER | Erick Lutz
INSTITUTE | University of Erlangen-Nuremberg
DATE | July 5(Tue), 2016
TIME | 15:40
PLACE | Korea Institute for Advanced Study (KIAS), Seoul, Korea
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
in time. According to the second law of thermodynamics, this arrow of time is associated
with a positive mean entropy production. We discuss the nonequilibrium entropy produced in
an isolated spin-1/2 system following fast quenches of an external magnetic field measured
using a nuclear magnetic resonance setup. We demonstrate that it is equal to the entropic
distance, expressed by the Kullback-Leibler divergence, between a microscopic process and
its time reversal.
T. B. Batalhao, A. M. Souza, R. S. Sarthour, I. S. Oliveira, M. Paternostro, E. Lutz, and R. M.
Serra, Phys. Rev. Lett. 115 (2015) 190601.