论文标题
Quantum Monte Carlo统计中杂质量子相变的足迹
Footprints of impurity quantum phase transitions in quantum Monte Carlo statistics
论文作者
论文摘要
与BCS超导导管连接的相互作用的单级量子点代表了一个可控制的系统，可以研究相关效应与电子配对之间的相互作用，该系统可能导致$0-π$（Singlet-Doublet）量子相变。杂质安德森模型可以很好地描述该系统的物理学。我们介绍了对这种一阶杂质量子相变附近的连续时间杂交量子量子量量的扰动扩展顺序的统计数据的分析。通过计算偏离理想高斯形状的膨胀顺序的直方图的矩，我们可以深入了解在低但有限温度下两个相的热力学混合，这反映在直方图的双峰性质中。
Interacting single-level quantum dot connected to BCS superconducting leads represents a well-controllable system to study the interplay between the correlation effects and the electron pairing that can result in a $0-π$ (singlet-doublet) quantum phase transition. The physics of this system can be well described by the impurity Anderson model. We present an analysis of the statistics of the perturbation expansion order of the continuous-time hybridization expansion quantum Monte Carlo algorithm in the vicinity of such a first-order impurity quantum phase transition. By calculating the moments of the histograms of the expansion order which deviate from the ideal Gaussian shape, we provide an insight into the thermodynamic mixing of the two phases at low but finite temperatures which is reflected in the bimodal nature of the histograms.
