论文标题
有效的低能模型，用于超导杂质系统
Effective low-energy models for superconducting impurity systems
论文作者
论文摘要
我们提出了两种互补方法，用于计算与超导杂质Anderson模型所描述的单级量子点的Andreev结合状态能量。第一种方法基于对低能模型的映射，可以利用从有限的，假想的时间量子蒙特卡洛数据中提取Andreev结合状态能量，而无需任何分析延续技术。第二种方法将完整的模型映射在可溶解的超导原子极限上，并具有重新归一化的参数。因此，它代表了快速扫描参数空间的快速可靠方法。我们证明，在添加简单的频带校正后，该方法可以为包括约瑟夫森电流在内的可测量量提供预测，这些量与数值重新归一化组和量子蒙特卡洛获得了可靠的定量一致性。
We present two complementary methods to calculate the Andreev bound state energies of a single-level quantum dot connected to superconducting leads described by the superconducting impurity Anderson model. The first method, which is based on a mapping to a low-energy model, can be utilized to extract the Andreev bound state energies from finite-temperature, imaginary-time quantum Monte Carlo data without the necessity of any analytic continuation technique. The second method maps the full model on an exactly solvable superconducting atomic limit with renormalized parameters. As such, it represents a fast and reliable method for a quick scan of the parameter space. We demonstrate that after adding a simple band correction this method can provide predictions for measurable quantities, including the Josephson current, that are in a solid quantitative agreement with precise results obtained by the numerical renormalization group and quantum Monte Carlo.
