Relaxation timescales versus interaction range in long-range quantum systems

Determine the dependence of relaxation time scales on the interaction range exponent α in long-range interacting quantum systems following a quantum quench, in regimes where relaxation is described by generalized Gibbs ensembles under the eigenstate thermalization hypothesis or quantum ergodic theory.

Background

The paper investigates non-equilibrium dynamics in one-dimensional Bose and fermion gases with long-range interactions decaying as 1/r^α, focusing on quenches from strongly repulsive to strongly attractive regimes. It analyzes relaxation via many-body entropies and observes violent fragmentation, Fock-space delocalization, and apparent classical-gas behavior.

While the authors characterize relaxation behavior across a broad range of α values and quench strengths, they highlight a general uncertainty about how relaxation times depend on the interaction range. This question is framed within the context of relaxation processes understood through generalized Gibbs ensembles and the eigenstate thermalization hypothesis.