Quenching across quantum critical points: Role of topological patterns

Sen, Diptiman and Vishveshwara, Smitha (2010) Quenching across quantum critical points: Role of topological patterns. In: EPL: Europhysics Letters, 91 (6).

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Abstract

We introduce a one-dimensional version of the Kitaev model consisting of spins on a two-legged ladder and characterized by Z(2) invariants on the plaquettes of the ladder. We map the model to a fermionic system and identify the topological sectors associated with different Z2 patterns in terms of fermion occupation numbers. Within these different sectors, we investigate the effect of a linear quench across a quantum critical point. We study the dominant behavior of the system by employing a Landau-Zener-type analysis of the effective Hamiltonian in the low-energy subspace for which the effective quenching can sometimes be non-linear. We show that the quenching leads to a residual energy which scales as a power of the quenching rate, and that the power depends on the topological sectors and their symmetry properties in a non-trivial way. This behavior is consistent with the general theory of quantum quenching, but with the correlation length exponent nu being different in different sectors. Copyright (C) EPLA, 2010

Item Type:	Journal Article
Publication:	EPL: Europhysics Letters
Publisher:	EDP Sciences
Additional Information:	Copyright of this article belongs to EDP Sciences.
Department/Centre:	Division of Physical & Mathematical Sciences > Centre for High Energy Physics
Date Deposited:	08 Mar 2011 06:34
Last Modified:	08 Mar 2011 06:34
URI:	http://eprints.iisc.ac.in/id/eprint/35901

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