APS March Meeting 2016
Volume 61, Number 2
Monday–Friday, March 14–18, 2016;
Baltimore, Maryland
Session A2: Frontiers in the Theory of Non-Equilibrium Physics: From Nanosystems to Cold Atoms
8:00 AM–11:00 AM,
Monday, March 14, 2016
Room: Ballroom II
Sponsoring
Units:
DCMP DAMOP
Chair: Marcos Rigol, Pennsylvania State University
Abstract ID: BAPS.2016.MAR.A2.3
Abstract: A2.00003 : \textbf{Non-equilibrium Aspects of Quantum Integrable Systems}*
9:12 AM–9:48 AM
Preview Abstract
Abstract
Author:
Natan Andrei
(Rutgers University)
The study of non-equilibrium dynamics of interacting many body systems is
currently one of the main challenges of modern condensed matter physics,
driven by the spectacular progress in the ability to create experimental
systems - trapped cold atomic gases are a prime example - that can be
isolated from their environment and be highly controlled. Many old and new
questions can be addressed: thermalization of isolated systems,
nonequilibrium steady states, the interplay between non equilibrium currents
and strong correlations, quantum phase transitions in time, universality
among others. In this talk I will describe nonequilibrium quench dynamics in
integrable quantum systems. I'll discuss the time evolution of the
Lieb-Liniger system, a gas of interacting bosons moving on the continuous
infinite line and interacting via a short range potential. Considering a
finite number of bosons on the line we find that for any value of repulsive
coupling the system asymptotes towards a strongly repulsive gas for any
initial state, while for an attractive coupling, the system forms a maximal
bound state that dominates at longer times. In the thermodynamic limit -with
the number of bosons and the system size sent to infinity at a constant
density and~the long time limit taken subsequently-~ I'll show that the
density and density-density correlation functions for strong but finite
positive coupling are described by GGE for translationally invariant initial
states with short~ range correlations. As examples I'll discuss quenches
from a Mott insulator initial state or a Newton's Cradle. Then I will show
that if the initial state is strongly non translational invariant, e.g. a
domain wall configuration, the system does not equilibrate but evolves into
a nonequilibrium steady state (NESS). A related NESS arises when the quench
consists of coupling a quantum dot to two leads held at different chemical
potential, leading in the long time limit to a steady state current. Time
permitting I will also discuss the quench dynamics of the XXZ Heisenberg
chain.
*Research supported by NSF Grant DMR 1410583
To cite this abstract, use the following reference: http://meetings.aps.org/link/BAPS.2016.MAR.A2.3