We establish efficient algorithms for weakly-interacting quantum spin systems at arbitrary temperature. In particular, we obtain a fully polynomial-time approximation scheme for the partition function and an efficient approximate sampling scheme for the thermal distribution over a classical spin space. Our approach is based on the cluster expansion method and a standard reduction from approximate sampling to approximate counting.

翻译：我们针对任意温度下的弱相互作用量子自旋系统建立了高效算法。具体而言，我们获得了配分函数的完全多项式时间近似方案，以及经典自旋空间上热分布的高效近似采样方案。我们的方法基于团簇展开技术，以及从近似采样到近似计数的标准归约。