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Griffiths phase in diluted magnetic semiconductors

Victor Galitski·A. Kaminski·S. Das Sarma
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Abstract

We study the effects of disorder in the vicinity of the ferromagnetic transition in a diluted magnetic semiconductor in the strongly localized regime. We derive an effective polaron Hamiltonian, which leads to the Griffiths phase above the ferromagnetic transition point. The Griffiths-McCoy effects yield non-perturbative contributions to the dynamic susceptibility. We explicitly derive the long-time susceptibility, which has a pseudo-scaling form, with the dynamic critical exponent being expressed through the percolation indices.

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Victor Galitski, A. Kaminski, S. Das Sarma. 2004-04-30. Griffiths phase in diluted magnetic semiconductors. https://doi.org/10.1103/physrevlett.92.177203

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