Timescale of ergodicity: when a many-body quantum systems can be described by the Random Matrix Theory?

23.11.2018 14:15 – 15:15

In this talk I will argue that dynamics of local
observables in quantum many-body systems is bounded in terms of the
"deviation function." The latter measures maximal possible deviation
from equilibrium for all states with a given energy variance. Using
this result I will define macroscopic thermalization time of quantum
many-body systems (Thouless time) in a state-independent way. I will
show that compatibility with classical transport impose stringent
constraints on deviation function, and in turn on matrix elements of
local observables. This leads to a bound on ergodicity time (the time
when dynamics of quantum system is described by random matrix theory
and exhibits universality) and a conjecture that it scales with the
system size as L^(d+2).

Lieu

Bâtiment: Ecole de Physique

Auditoire Stueckelberg

entrée libre