An extensive equilibrium Monte Carlo simulation is performed on the three-dimensional isotropic Heisenberg spin-glass (SG) model with the random nearest-neighbor Gaussian coupling, with particular interest in its chiral-glass (CG) and SG orderings. For this model, the possibility of the spin-chirality decoupling, i.e., the CG order setting in at a higher temperature than that of the SG order, was suggested earlier but still remains controversial. We simulate the model up to the maximum size (linear dimension) $L=48$ under both periodic and open boundary conditions (BCs). In locating the CG and SG transition temperatures $T_{\mathrm{CG}}$ and $T_{\mathrm{SG}}$ with the $L\to \infty$ extrapolation, a variety of independent physical quantities under both BCs are computed and utilized to get larger number of degrees of freedom (NDF). Because of the large NDF up to $\text{NDF}=43$, we succeed in obtaining stable and accurate estimates of the CG and SG transition temperatures, $T_{\mathrm{CG}}=0.142\pm 0.001$ and $T_{\mathrm{SG}}=0.{131}_{-0.006}^{+0.001}$. No sign of the size crossover is observed. For larger $L$, the CG correlation length progressively outgrows the SG correlation length at low temperatures. These results provide strong numerical support for the spin-chirality decoupling. The critical exponents associated with the CG and SG transitions are evaluated using the finite-size scaling with the scaling correction. For the CG transition, we get the CG exponents, ${\nu }_{\mathrm{CG}}=1.36\pm 0.10$ and ${\eta }_{\mathrm{CG}}=0.49\pm 0.10$, consistent with the corresponding experimental exponents of canonical SG. Implications for the chirality scenario of experimental SG ordering are discussed.

中文翻译：

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蒙特卡洛研究三维海森堡自旋玻璃中的自旋手性解耦

在具有各向同性随机高斯耦合的三维各向同性海森堡自旋玻璃（SG）模型上进行了广泛的平衡蒙特卡洛模拟，特别是对其手性玻璃（CG）和SG的排序感兴趣。对于该模型，较早提出了自旋手性去耦的可能性，即CG顺序设置在比SG顺序更高的温度下，但仍然存在争议。我们模拟模型直至最大尺寸（线性尺寸）$\mathrm{大号}=48$在周期性和开放边界条件（BCs）下。确定CG和SG的转变温度${Ť}_{\mathrm{CG}}$ 和 ${Ť}_{\mathrm{SG}}$ 与 $\mathrm{大号}\to \infty$外推法计算两个BC下的各种独立物理量，并利用它们获得更多的自由度（NDF）。由于NDF较大，$\text{NDF}=43$，我们成功获得了CG和SG转变温度的稳定且准确的估算值， ${Ť}_{\mathrm{CG}}=0.142\pm 0.001$ 和 ${Ť}_{\mathrm{SG}}=0。{131}_{-0.006}^{+0.001}$。没有观察到尺寸交叉的迹象。对于更大$\mathrm{大号}$，CG相关长度在低温下逐渐超过SG相关长度。这些结果为自旋手性解耦提供了有力的数值支持。使用带有缩放校正的有限大小缩放，可以评估与CG和SG过渡相关的临界指数。对于CG过渡，我们得到了CG指数，${\nu }_{\mathrm{CG}}=1.36\pm 0.10$ 和 ${\eta }_{\mathrm{CG}}=0.49\pm 0.10$，与规范SG的相应实验指数一致。讨论了实验性SG有序手性方案的含义。