论文标题
有限的频率反向散射电流噪声在螺旋边缘
Finite frequency backscattering current noise at a helical edge
论文作者
论文摘要
具有足够各向异性的磁杂质可以解释2D拓扑绝缘子与预期的量化值的边缘电导的强偏差。在这项工作中，我们认为这样的螺旋边缘与任意旋转$ s $和一般形式的Exchange矩阵稀释杂质相结合。我们计算有限频率下的反向散射电流噪声，这是温度和施加的电压偏置的函数。我们发现，除了以零频率的洛伦兹共振之外，反向散射的电流噪声还具有非零频率下的fano型共振。共振的宽度由相应的Korringa速率的光谱控制。在固定频率下，反向散射电流噪声具有非单调的行为与偏置电压的函数。
Magnetic impurities with sufficient anisotropy could account for the observed strong deviation of the edge conductance of 2D topological insulators from the anticipated quantized value. In this work we consider such a helical edge coupled to dilute impurities with an arbitrary spin $S$ and a general form of the exchange matrix. We calculate the backscattering current noise at finite frequencies as a function of the temperature and applied voltage bias. We find that in addition to the Lorentzian resonance at zero frequency, the backscattering current noise features Fano-type resonances at non-zero frequencies. The widths of the resonances are controlled by the spectrum of corresponding Korringa rates. At a fixed frequency the backscattering current noise has non-monotonic behaviour as a function of the bias voltage.
