Spreading in Integrable and Non--integrable Many--body Systems

TL;DR

This paper investigates how energy redistributes in both integrable and non-integrable many-body systems, highlighting conditions for spreading and its relation to thermalization.

Contribution

It identifies subtle features that determine the onset of spreading in integrable systems and compares these with non-integrable systems.

Findings

Spreading can occur in integrable systems without thermalization.

Certain features influence the onset of spreading in integrable models.

Comparison shows differences and similarities between integrable and non-integrable cases.

Abstract

We consider a finite, closed and selfbound many--body system in which a collective degree of freedom is excited. The redistribution of energy and momentum into a finite number of the non-collective degrees of freedom is referred to as spreading as opposed to damping in open systems. Spreading closely relates to thermalization, but while thermalization requires non-integrability, spreading can also present in integrable systems. We identify subtle features which determine the onset of spreading in an integrable model and compare the result with a non--integrable case.