Thursday's talk

[CM ICTP - Trieste]

SEMINAR on



Disorder and strong electron correlations





Thursday, 25 September      -  11:00 a.m.





Seminar Room,  Leonardo Bldg.- first floor





A. SILVA ( I.C.T.P. )



"The statistics of the work done in a quantum quench"



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 nonequilibrium process, which has  
been realized recently in the context of cold atoms, is of particular  
interest in quantum critical systems. In this talk I will discuss a  
fundamental way to characterize these processes using basic  
thermodynamic variables and looking at their statistics. Focusing on  
the statistics of

the work done in a quantum quench I will first elucidate the relation  
between the probability distribution of the work, quantum Jarzynski  
equalities, and the Loschmidt echo, a quantity that emerges usually  
in the context of dephasing. Using this connection, I will then  
characterize the statistics of the work done on a quantum Ising chain  
by quenching locally

or globally the transverse field, showing that for local quenches  
starting at criticality, the probability distribution of the work  
displays an interesting edge singularity.



Ref: Alessandro Silva, Phys. Rev. Lett. 101, 120603 (2008).