Critical Points and Quenched Disorder: from Harris Criterion to Rare Regions and Smearing

Abstract

We consider the influence of quenched spatial disorder on phase transitions in classical and quantum systems. We show that rare strong disorder fluctuations can have dramatic effects on critical points. in classical systems with sufficiently correlated disorder or in quantum systems with overdamped dynamics they can completely destroy the sharp phase transition by smearing. This is caused by effects similar to but stronger than Griffiths phenomena: True static order can develop on a rare region while the bulk system is still in the disordered phase. We discuss the thermodynamic behavior in the vicinity of such a smeared transition using optimal fluctuation theory, and we present numerical results for a two-dimensional model system. (© 2004 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)

Department(s)

Physics

Sponsor(s)

University of Missouri Research Board

Keywords and Phrases

Critical Points; Harris Criterion; Quenched Disorder

Document Type

Article - Journal

Document Version

Citation

File Type

text

Language(s)

English

Rights

© 2004 Wiley-Blackwell, All rights reserved.

Publication Date

01 Jan 2004

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