Speaker
Alessandro Silva
(ICTP, Trieste)
Description
I will describe recent studies of the dynamics of spin chains
following a quench of one of the system parameters
focusing on the characterization of relaxation and of the
asymptotic state in relation to the integrability of the model.
A detailed staudy of various model, such as the Quantum
Ising and XXZ chains, suggests that for integrable system
the behavior of two-point spin correlation functions shows
that the correlators of operators that are non-local with
respect to the quasiparticles of the model display an
effective asymptotic thermal behavior. On the contrary, the
two point correlation functions of operators that are local
with respect to the quasiparticles do not behave thermally.
A sufficiently strong integrability-breaking term, which
induces thermalization to occur in general, both for local
and non-local observables. I will discuss how this
phenomenon is deeply rooted in a many-body
localization/delocalization transition, i.e. is associated to a
crossover/transition from localized to delocalized states in
quasi-particle space.
