Optical conductivity of the Fröhlich polaron.
Optical conductivity of the Fröhlich polaron.
复制标题
Fröhlich 极化子的光导率。
DOI：
10.1103/physrevlett.91.236401
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发表时间：
2003
影响因子：
8.6
通讯作者：
B. Svistunov
中科院分区：
文献类型：
--
作者：
A. Mishchenko;N. Nagaosa;N. Prokof'ev;A. Sakamoto;B. Svistunov
本文给出了三维Fröhlich极化子在所有耦合区的电导率的精确结果。本文采用无系统误差的图解量子蒙特卡罗方法，计算了虚时间动量-动量关联函数的费曼图。通过随机优化解析延拓法得到了实频电导率。我们比较数值数据与现有的微扰和非微扰的方法的光学电导率和显示，由于在强耦合制度的放松激发态的尖锐共振的图片是“洗”这些国家的大加宽。因此，光谱只包含一个具有特殊形状和肩部的单最大宽峰。
We present accurate results for optical conductivity of the three dimensional Fröhlich polaron in all coupling regimes. The systematic-error free diagrammatic quantum Monte Carlo method is employed where the Feynman graphs for the momentum-momentum correlation function in imaginary time are summed up. The real-frequency optical conductivity is obtained by the analytic continuation with stochastic optimization. We compare numerical data with available perturbative and nonperturbative approaches to the optical conductivity and show that the picture of sharp resonances due to relaxed excited states in the strong-coupling regime is "washed out" by large broadening of these states. As a result, the spectrum contains only a single-maximum broad peak with peculiar shape and a shoulder.