Ensemble dependence in the random transverse-field Ising chain

Dhar, Abhishek ; Young, A. P. (2003) Ensemble dependence in the random transverse-field Ising chain Physical Review B: Condensed Matter and Materials Physics, 68 (13). 134441_1-134441_8. ISSN 1098-0121

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Official URL: http://prb.aps.org/abstract/PRB/v68/i13/e134441

Related URL: http://dx.doi.org/10.1103/PhysRevB.68.134441


In a disordered system one can either consider a microcanonical ensemble, where there is a precise constraint on the random variables, or a canonical ensemble where the variables are chosen according to a distribution without constraints. We address the question as to whether critical exponents in these two cases can differ through a detailed study of the random transverse-field Ising chain. We find that the exponents are the same in both ensembles, though some critical amplitudes vanish in the microcanonical ensemble for correlations which span the whole system and are particularly sensitive to the constraint. This can appear as a different exponent. We expect that this apparent dependence of exponents on ensemble is related to the integrability of the model, and would not occur in non-integrable models.

Item Type:Article
Source:Copyright of this article belongs to The American Physical Society.
ID Code:79697
Deposited On:28 Jan 2012 12:07
Last Modified:18 May 2016 21:58

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