Max-Planck-Institut für Physik komplexer Systeme, 01187 Dresden, Germany and Theoretical Division, Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA and Department of Physics, University of Wisconsin, Madison, Wisconsin 53706, USA.
Max-Planck-Institut für Physik komplexer Systeme, 01187 Dresden, Germany.
Phys Rev Lett. 2013 Feb 15;110(7):077201. doi: 10.1103/PhysRevLett.110.077201. Epub 2013 Feb 11.
Ever since the experiments which founded the field of highly frustrated magnetism, the kagome Heisenberg antiferromagnet has been the archetypical setting for the study of fluctuation induced exotic ordering. To this day the nature of its classical low-temperature state has remained a mystery: the nonlinear nature of the fluctuations around the exponentially numerous harmonically degenerate ground states has not permitted a controlled theory, while its complex energy landscape has precluded numerical simulations at low temperature, T. Here we present an efficient Monte Carlo algorithm which removes the latter obstacle. Our simulations detect a low-temperature regime in which correlations asymptote to a remarkably small value as T→0. Feeding these results into an effective model and analyzing the results in the framework of an appropriate field theory implies the presence of long-range dipolar spin order with a tripled unit cell.
自从开创高度受挫磁性领域的实验以来， kagome Heisenberg 反铁磁体一直是研究波动诱导奇异有序的典型环境。直到今天，其经典低温状态的性质仍然是一个谜：围绕指数数量的简谐简并基态的波动的非线性性质不允许进行受控理论，而其复杂的能量景观则排除了低温 T 下的数值模拟。在这里，我们提出了一种有效的蒙特卡罗算法，该算法消除了后者的障碍。我们的模拟检测到低温状态，其中相关项随着 T→0 趋于非常小的值。将这些结果输入到有效模型中，并在适当的场论框架中分析结果，意味着存在具有三倍单元的长程偶极自旋有序。
