Quantum phase transition in the sub-Ohmic spin-boson model: quantum Monte Carlo study with a continuous imaginary time cluster algorithm.
Quantum phase transition in the sub-Ohmic spin-boson model: quantum Monte Carlo study with a continuous imaginary time cluster algorithm.
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DOI：
10.1103/physrevlett.102.030601
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发表时间：
2008-07
影响因子：
8.6
通讯作者：
A. Winter;H. Rieger;M. Vojta;R. Bulla
中科院分区：
文献类型：
--
作者：
A. Winter;H. Rieger;M. Vojta;R. Bulla
提出了耦合到耗散玻色子浴的两能级系统的连续时间聚类算法，并将其应用于亚欧姆自旋玻色子模型。当谱函数 Jomega 比例、变体 omegas 的幂 s 小于 1/2 时，发现临界指数是经典的、类平均场的。与最近的重正化群预测的差异的潜在根源可以追溯到危险的不相关变量的影响。
A continuous time cluster algorithm for two-level systems coupled to a dissipative bosonic bath is presented and applied to the sub-Ohmic spin-boson model. When the power s of the spectral function Jomega proportional, variant omegas is smaller than 1/2, the critical exponents are found to be classical, mean-field like. Potential sources for the discrepancy with recent renormalization group predictions are traced back to the effect of a dangerously irrelevant variable.