The distribution of heat exchanged between two quantum spin chains

Gabriel T. Landi

Published 2014-12-13Version 1

We study the distribution of heat values exchanged between two quantum XX chains prepared at different temperatures. It is found that the system approximately obeys the Jarzynski-W\'ojcik exchange fluctuation theorem for large chain sizes and/or small coupling constant. We also analyze the average heat and find that finite chains do not thermalize, not even on average. In the thermodynamic limit, on the other hand, thermalization does occur. However, the average heat as a function of time is not necessarily a monotonically changing function, but may oscillate toward equilibrium depending on the initial temperatures of the chains.