Defect production due to quenching through a multicritical point

Divakaran, Uma and Mukherjee, Victor and Dutta, Amit and Sen, Diptiman (2009) Defect production due to quenching through a multicritical point. In: Journal Of Statistical Mechanics-Theory And Experiment . P02007-1-P02007-8.

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Abstract

We study the generation of defects when a quantum spin system is quenched through a multicritical point by changing a parameter of the Hamiltonian as t/tau, where tau is the characteristic timescale of quenching. We argue that when a quantum system is quenched across a multicritical point, the density of defects (n) in the final state is not necessarily given by the Kibble-Zurek scaling form n similar to 1/tau(d nu)/((z nu+1)), where d is the spatial dimension, and. and z are respectively the correlation length and dynamical exponent associated with the quantum critical point. We propose a generalized scaling form of the defect density given by n similar to 1/(tau d/(2z2)), where the exponent z(2) determines the behavior of the off-diagonal term of the 2 x 2 Landau-Zener matrix at the multicritical point. This scaling is valid not only at a multicritical point but also at an ordinary critical point.

Item Type:	Journal Article
Publication:	Journal Of Statistical Mechanics-Theory And Experiment
Publisher:	Institute of Physics
Additional Information:	Copyright of this article belongs to Institute of Physics.
Keywords:	integrable spin chains (vertex models);spin chains;ladders and planes (theory);quantum phase transitions (theory).
Department/Centre:	Division of Physical & Mathematical Sciences > Centre for High Energy Physics Division of Physical & Mathematical Sciences > Physics
Date Deposited:	30 Apr 2009 04:32
Last Modified:	19 Sep 2010 05:29
URI:	http://eprints.iisc.ac.in/id/eprint/19561

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