Quantum Griffiths effects and smeared phase transitions in metals: theory and experiment
Abstract
In this paper, we review theoretical and experimental research on rare region effects at quantum phase transitions in disordered itinerant electron systems. After summarizing a few basic concepts about phase transitions in the presence of quenched randomness, we introduce the idea of rare regions and discuss their importance. We then analyze in detail the different phenomena that can arise at magnetic quantum phase transitions in disordered metals, including quantum Griffiths singularities, smeared phase transitions, and cluster-glass formation. For each scenario, we discuss the resulting phase diagram and summarize the behavior of various observables. We then review several recent experiments that provide examples of these rare region phenomena. We conclude by discussing limitations of current approaches and open questions.
Keywords
Cite
@article{arxiv.1005.2707,
title = {Quantum Griffiths effects and smeared phase transitions in metals: theory and experiment},
author = {Thomas Vojta},
journal= {arXiv preprint arXiv:1005.2707},
year = {2010}
}
Comments
31 pages, 7 eps figures included, v2: discussion of the dissipative Ising chain fixed, references added, v3: final version as published