Collège Doctoral - Doktorandenkollegien

Statistical Physics of Complex Systems

Coventry - Leipzig - Lviv - Nancy

PhD positions


Space-Time quantum quenches
Mario Collura
propriomario AT tiscali DOT it
Laboratoire de Physique des Matériaux (Nancy 1)
le Thursday 05 November 2009 à 14h30
Institut für Theoretische Physik, large seminar room.
We consider a quantum system with a power-law deviation from the critical couplings such that the system is critical at its surface. We study the temporal behaviour of a such system under a slow power-law quench which drives the system through a second order quantum phase transition. Using scaling arguments we show that around the critical locus (put in x=0,t=0) appears a crossover region with spatial lenght λ and temporal lenght τ that scale with the adiabaticity rate v as a power related either to the critical exponents z an ν characterizing the phase transition and to the exponents ω and α characterizing the spatial deviation of the couplings and the temporal quench, respectively. We support general scaling arguments by applying the trap-size scaling in the framework of the adiabatic perturbative expansion. We supplement our results with both analytical and numerical studies of the Ising quantum chain.

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