MONTE-CARLO STUDY OF CHIRAL CRITICALITY - XY AND HEISENBERG STACKED-TRIANGULAR ANTIFERROMAGNETS
MONTE-CARLO STUDY OF CHIRAL CRITICALITY - XY AND HEISENBERG STACKED-TRIANGULAR ANTIFERROMAGNETS
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DOI：
10.1143/jpsj.61.1299
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发表时间：
1992-04-01
影响因子：
1.7
通讯作者：
KAWAMURA, H
中科院分区：
文献类型：
--
作者：
KAWAMURA, H
本文报道了d = 3维叠三角晶格上XY和Heisenberg反铁磁体的蒙特卡罗模拟结果，预计它们分别属于最近确定的n = 2和3手性普适类。研究的晶格由L3个自旋组成，其中18个小于等于L个小于等于60个。该研究是早期蒙特卡罗模拟的扩展，用于具有较小格点的相同系统。在XY （n = 2）的情况下，alpha = 0.34 +/- 0.06, beta = 0.253 +/- 0.01, gamma = 1.13 +/- 0.05, nu = 0.54 +/- 0.02；在Heisenberg （n = 3）的情况下，alpha = 0.24 +/- 0.08, beta = 0.30 +/- 0.02, gamma = 1.17 +/- 0.07, nu = 0.59 +/- 0.02。在n = 2和n = 3情况下，比热幅值比分别为A+/A- = 0.36 +/- 0.2和A+/A- = 0.54 +/- 0.2。研究了手性有序的性质，确定了各种手性指数。结合最近的重整化群计算和实验对结果进行了讨论。
The results of extensive Monte Carlo simulations are reported on XY and Heisenberg antiferromagnets on a d = 3-dimensional stacked-triangular lattice, which are expected to belong to the recently identified n = 2 and 3 chiral universality classes, respectively. The lattices studied consist of L3 spins with 18 less-than-or-equal-to L less-than-or-equal-to 60. The study is an extension of earlier Monte Carlo simulations for the same system with smaller lattices. A continuous transition characterized by the novel critical exponents is found with alpha = 0.34 +/- 0.06, beta = 0.253 +/- 0.01, gamma = 1.13 +/- 0.05 and nu = 0.54 +/- 0.02 for the XY (n = 2) case, and with alpha = 0.24 +/- 0.08, beta = 0.30 +/- 0.02, gamma = 1.17 +/- 0.07 and nu = 0.59 +/- 0.02 for the Heisenberg (n = 3) case. The specific-heat amplitude ratio is estimated to be A+/A- = 0.36 +/- 0.2 and A+/A- = 0.54 +/- 0.2 in the n = 2 and n = 3 cases, respectively. The nature of the chiral ordering is also studied, and various chirality exponents are determined. The results are discussed in conjunction with the recent renormalization-group calculations and experiments.