Green's Functions from Quantum Cluster Algorithms
Green's Functions from Quantum Cluster Algorithms
复制标题
量子簇算法中的格林函数
DOI：
10.1016/s0378-4371(98)00325-2
复制
发表时间：
1998
影响因子：
3.3
通讯作者：
Uwe
中科院分区：
文献类型：
--
作者：
Richard C. Brower;Richard C. Brower;S. Chandrasekharan;S. Chandrasekharan;Uwe
我们表明，用于量子模型的集群算法具有独立于构建它们的基的意义。利用这一思想，我们提出了一种新的方法，一旦构建了配分函数的聚类算法，就可以很容易地测量一整类格林函数。为了解释这一思想，我们考虑了量子XY模型，并用不同的方法计算了它的两点格林函数，表明它们都是等价的。我们还提供了数字证据，证实了分析的论点。类似的技术也适用于其他模型。特别是，在最近建立的量子链模型中，新技术允许我们构建改进的威尔逊环估计器，并可能导致非常精确的胶球光谱确定。
We show that cluster algorithms for quantum models have a meaning independent of the basis chosen to construct them. Using this idea, we propose a new method for measuring with little effort a whole class of Green’s functions, once a cluster algorithm for the partition function has been constructed. To explain the idea, we consider the quantum XY model and compute its two point Green’s function in various ways, showing that all of them are equivalent. We also provide numerical evidence confirming the analytic arguments. Similar techniques are applicable to other models. In particular, in the recently constructed quantum link models, the new technique allows us to construct improved estimators for Wilson loops and may lead to a very precise determination of the glueball spectrum.