Thursday seminar

[CM ICTP - Trieste]

SEMINAR on   Disorder and strong electron correlations



Thursday, 12 February      -  11:00 a.m.



Seminar Room,  Leonardo Building - first floor



S.R. MANMANA  ( Ecole Polytechnique Federale de Lausanne )



" Time evolution of correlations in strongly interacting fermions and  
bosons "



Abstract



Using the adaptive time-dependent density matrix renormalization  
group, we study the time evolution of strongly correlated bosonic and  
fermionic systems on one-dimensional lattices pushed out of  
equilibrium. In particular, we investigate a system of interacting  
spinless fermions after a sudden change in the interaction strength  
and a system of soft- core bosons modeled by the Bose-Hubbard model  
released from a trapping box-potential. By considering the momentum  
distribution function of the bosonic system, we demonstrate the  
formation of (quasi-)coherent matter waves emerging from an initial  
Mott insulating state over a wide range of the interaction strength  
between the particles. In the fermionic system, we find the density  
correlations to exhibit a characteristic light-cone-like time  
evolution which is representative of a ballistic transport of  
information. Such behavior is observed both

when quenching an insulator into the metallic region and also when  
quenching within the insulating region, but not  when a metallic  
state is quenched deep into the insulating regime. Instead, stable  
domain walls in the density correlations emerge during the time  
evolution, consistent with the predictions of the Kibble-Zurek  
mechanism.