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Field-induced Bose-Einstein condensation of interacting dilute magnons in three-dimensional spin systems: A renormalization-group study

M. Crisan·I. Tifrea·D Bodea·I. Grosu
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Abstract

We use the Renormalization Group method to study the magnetic field influence on the Bose-Einstein condensation of interacting dilute magnons in three dimensional spin systems. We first considered a model with SU(2) symmetry (universality class $z=1$) and we obtain for the critical magnetic field a power law dependence on the critical temperature, $[H_c(T)-H_c(0)]\sim T^2$. In the case of U(1) symmetry (universality class $z=2$) the dependence is different, and the magnetic critical field depends linearly on the critical temperature, $[H_c(T)-H_c(0)]\sim T$. By considering a more relevant model, which includes also the system's anisotropy, we obtain for the same symmetry class a $T^{3/2}$ dependence of the magnetic critical field on the critical temperature. We discuss these theoretical predictions of the renormalization group in connection with experimental results reported in the literature.

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M. Crisan, I. Tifrea, D Bodea, I. Grosu. 2005-11-16. Field-induced Bose-Einstein condensation of interacting dilute magnons in three-dimensional spin systems: A renormalization-group study. https://doi.org/10.1103/physrevb.72.184414

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