Quench dynamics across quantum critical points

Sengupta, K. ; Powell, Stephen ; Sachdev, Subir (2004) Quench dynamics across quantum critical points Physical Review A, 69 (5). 053616_1-053616_10. ISSN 1050-2947

[img]
Preview
PDF - Author Version
308kB

Official URL: http://pra.aps.org/abstract/PRA/v69/i5/e053616

Related URL: http://dx.doi.org/10.1103/PhysRevA.69.053616

Abstract

We study the quantum dynamics of a number of model systems as their coupling constants are changed rapidly across a quantum critical point. The primary motivation is provided by the recent experiments of Greiner et al. [Nature (London) 415, 39 (2002)] who studied the response of a Mott insulator of ultracold atoms in an optical lattice to a strong potential gradient. In a previous work, it had been argued that the resonant response observed at a critical potential gradient could be understood by proximity to an Ising quantum critical point describing the onset of density wave order. Here we obtain numerical results on the evolution of the density wave order as the potential gradient is scanned across the quantum critical point. This is supplemented by studies of the integrable quantum Ising spin chain in a transverse field, where we obtain exact results for the evolution of the Ising order correlations under a time-dependent transverse field. We also study the evolution of transverse superfluid order in the three-dimensional case. In all cases, the order parameter is best enhanced in the vicinity of the quantum critical point.

Item Type:Article
Source:Copyright of this article belongs to The American Physical Society.
ID Code:81324
Deposited On:06 Feb 2012 05:06
Last Modified:18 May 2016 22:56

Repository Staff Only: item control page