On the theory of Bose-Einstein condensation of quasiparticles: on the possibility of condensation of magnons at high temperatures

A. I. Bugrij; V. M. Loktev

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On the theory of Bose-Einstein condensation of quasiparticles: on the possibility of condensation of magnons at high temperatures

A. I. Bugrij·V. M. Loktev

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Abstract

Bose condensation of quasiparticles in physical systems of finite size iz considered for the case of ferromagnetic thin films. It is shown that in accordance with present-day experimental capabilities which permit one to achieve densities of long-wave spin excitation of 1018-1019 cm-3, in such films the formation of condensate of such quasiparticles begins at temperatures T~100 K (room one including). It is found that Bose condensation is accompanied by scaling phenomenon according to which the main thermodynamic variable is not the number N of particles but the ratio N/T. This indicates that condensation of magnons can be observed at relatively low magnon densities. The roles played by the shape of the spectrum and film thickness are analyzed.

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A. I. Bugrij, V. M. Loktev. 2007-01-18. On the theory of Bose-Einstein condensation of quasiparticles: on the possibility of condensation of magnons at high temperatures. https://arxiv.org/abs/cond-mat/0701437

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