Speaker
Prof.
Alexander Altland
(Köln Universität)
Description
We will discuss mechanisms of effective equilibration
('thermalization') for unitary quantum dynamics under
conditions of classical chaos. Focusing on the paradigmatic
example of the Dicke model, we will explore how a
constructive description of the thermalization process is
facilitated by the Glauber Q or Husimi function, for which
the evolution equation turns out to be of Fokker-Planck
type. The equation describes a competition of classical
drift and quantum diffusion in contractive and expansive
directions. By this mechanism the system follows a ’quantum
smoothened’ approach to equilibrium, which avoids the
notorious singularities inherent to classical chaotic flows.
Other universal signatures of the equilibration of nonlinear
quantum systems will be discussed on the toy model of a
nonlinear ocillator mode.
Primary author
Prof.
Alexander Altland
(Köln Universität)
