Thursday's seminar

[CM]

SEMINAR on   Disorder and strong electron correlations





Thursday, 1 October      -  11:00 a.m.





Seminar Room,  Leonardo Building - first floor





Alessandro SILVA     ( The Abdus Salam ICTP )



"Universal physics in quantum nonequilibrium processes: Quantum  
quenches, work statistics and edge singularities"



Abstract



A quantum quench is a rapid change in time of a control parameter in  
the Hamiltonian describing a quantum, correlated many-body system.   
The physics of this paradigmatic non-equilibrium process, which has  
been realized recently in the context of cold atoms, is of particular  
interest in quantum critical systems where concrete dynamical  
manifestations of universality can be studied.  In this talk I will  
discuss two fundamental ways to characterize these processes, by  
either looking at the statistics of basic thermodynamic variables or  
at the asymptotics of correlators.  I will first elucidate the  
connection between a classic problem in condensed matter physics, the   
Fermi edge singularity, the statistics of the work done in a quantum   
quench, and quantum Jarzynski equalities.  Using this connection, I  
will discuss results for the statistics of the work in a variety of  
systems, such as the quantum Ising chain, the Dicke model and quantum  
impurities.  I will show that quantum criticality manifests itself in  
the emergence of interesting edge singularities in the statistics of  
the work and discuss their universality.  Similarly, I will discuss  
how the critical properties are encoded in the asymptotics of non- 
equilibrium correlators.