Upcoming ICTP/SISSA Stat.Physics Seminar

[Statistical Physics]

JOINT ICTP/SISSA STATISTICAL PHYSICS SEMINAR


Thursday, 10 July - 11:00 a.m.*
*

SISSA, Santorio Building,  Room 138


*****************************************************************

Speaker: Marton KORMOS  (Budapest)

Title: Quantum Quenches in the XXZ spin chain and the Generalized Gibbs 
Ensemble

Abstract:

Isolated integrable quantum systems do not relax to a thermal state even 
locally due
to the extra conserved quantities that they possess. The so-called 
Generalized Gibbs
Ensemble (GGE) was proposed to capture the steady state of integrable 
systems, but
it has not been put to a stringent test for genuinely interacting systems.
In the talk I will review our work on the non-equilibrium time evolution 
of the spin-1/2
anisotropic Heisenberg (XXZ) spin chain, where we found that 
short-ranged spin
correlators in the long-time limit deviate significantly from 
predictions based on the GGE
hypothesis.
By computing the asymptotic spin correlators within the quench action 
formalism based
on exact overlaps, however, we find excellent agreement with the 
numerical data. I will
show why this result can be considered as conclusive evidence for the 
failure of the GGE
and I will discuss the possible implications of this finding.