Some speculations about local thermalization of nonequilibrium extended quantum systems

Abstract

We discuss the possibility of defining an emergent local temperature in extended quantum many-body systems evolving out of equilibrium. For the most simple case of free-fermionic systems, we give an explicit formula for the effective temperature in the case of, not necessarily unitary, Gaussian preserving dynamics. In this framework, we consider the hopping fermions on a one-dimensional lattice submitted to randomly distributed projective measurements of the local occupation numbers. We show from the average over many quantum trajectories that the effective temperature relaxes exponentially towards infinity.

13 pages, 1 figure

References in corpus (8)

• Thermalization and its mechanism for generic isolated quantum systems
• Open XXZ spin chain: Nonequilibrium steady state and strict bound on ballistic transport
• Evolution of entanglement after a local quench
• Existence of temperature on the nanoscale
• Relaxation in the XX quantum chain
• The open Heisenberg chain under boundary fields: a magnonic logic gate
• Fluctuations in subsystems of the zero temperature XX chain: Emergence of an effective temperature
• Hydrodynamic description of Hard-core Bosons on a Galileo ramp