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A Tale of Two Theories: Quantum Griffiths Effects in Metallic Systems

A. H. Castro Neto·B. A. Jones
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Abstract

We show that two apparently contradictory theories on the existence of Griffiths-McCoy singularities in magnetic metallic systems [1,2] are in fact mathematically equivalent. We discuss the generic phase diagram of the problem and show that there is a non-universal crossover temperature range T* < T < W where power law behavior (Griffiths-McCoy behavior) is expect. For T<T* power law behavior ceases to exist due to the destruction of quantum effects generated by the dissipation in the metallic environment. We show that T* is an analogue of the Kondo temperature and is controlled by non-universal couplings.

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A. H. Castro Neto, B. A. Jones. 2004-11-08. A Tale of Two Theories: Quantum Griffiths Effects in Metallic Systems. https://doi.org/10.1209/epl%2Fi2005-10138-7

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