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Monte Carlo study of the critical temperature for the planar rotator model with nonmagnetic impurities

S. A. Leonel·Pablo Zimmermann Coura·A. R. Pereira·L. A. S. Mól·B. V. Costa
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Abstract

We performed Monte Carlo simulations to calculate the Berezinskii-Kosterlitz-Thouless (BKT) temperature $T_{BKT}$ for the two-dimensional planar rotator model in the presence of nonmagnetic impurity concentration $(ρ)$. As expected, our calculation shows that the BKT temperature decreases as the spin vacancies increase. There is a critical dilution $ρ_c \approx 0.3$ at which $T_{BKT} =0$. The effective interaction between a vortex-antivortex pair and a static nonmagnetic impurity is studied analytically. A simple phenomenological argument based on the pair-impurity interaction is proposed to justify the simulations.

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S. A. Leonel, Pablo Zimmermann Coura, A. R. Pereira, L. A. S. Mól, B. V. Costa. 2002-10-09. Monte Carlo study of the critical temperature for the planar rotator model with nonmagnetic impurities. https://doi.org/10.1103/physrevb.67.104426

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