On the sign problem in the Hirsch-Fye algorithm for impurity problems
On the sign problem in the Hirsch-Fye algorithm for impurity problems
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关于Hirsch-Fye算法中杂质问题的符号问题
DOI：
10.1088/0305-4470/38/48/004
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发表时间：
2004
期刊：
影响因子：
--
通讯作者：
H. Baranger
中科院分区：
文献类型：
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作者：
Jaebeom Yoo;S. Chandrasekharan;R. Kaul;D. Ullmo;H. Baranger
证明了单杂质安德森模型的Hirsch和Fye算法不存在费米子符号问题。除了存在简单证明的粒子-空穴对称情况之外，这只是经验性的。在这里，我们证明了不存在的一般情况下，一个符号的问题表明，每个自旋轨迹为一个给定的伊辛配置是分别积极的。我们进一步利用这一认识分析了轨道简并的安德森模型或双杂质安德森模型在什么条件下产生符号。
We show that there is no fermion sign problem in the Hirsch and Fye algorithm for the single-impurity Anderson model. Beyond the particle-hole symmetric case for which a simple proof exists, this has been known only empirically. Here we prove the nonexistence of a sign problem for the general case by showing that each spin trace for a given Ising configuration is separately positive. We further use this insight to analyse under what conditions orbitally degenerate Anderson models or the two-impurity Anderson model develop a sign.