论文标题
射击噪声和通用的Fano因子，作为强相关金属的表征
Shot noise and universal Fano factor as characterization of strongly correlated metals
论文作者
论文摘要
射击噪声测量值不平衡电流波动，是探测量子系统中电流激发性质的强大工具。最近的射击噪声测量值奇怪的金属ybrh $ _2 $ si $ _2 $表现出对Fano因子的强烈抑制（$ f $） - 当前噪声与直流限制中的平均电流的比率。该系统代表了电子相关性极强的金属。在这里，我们进行了第一项关于在强相关性方面扩散金属的射击噪声的理论研究。在存在很强相关性的情况下，在准粒子描述中构建了玻尔兹曼 - 兰格方程式公式。我们发现在这种相关性方面，$ f = \ sqrt {3}/{4} $。因此，我们将上述的FANO因子与费米液体定义为通用，并表明在YBRH $ _2 $ _2 $ si $ _2 $的实验中观察到的Fano因子抑制作用需要损失准粒子。我们的工作为射击噪声的系统理论研究打开了大门，作为表征强相关的金属相和材料的一种手段。
Shot noise measures out-of-equilibrium current fluctuations and is a powerful tool to probe the nature of current-carrying excitations in quantum systems. Recent shot noise measurements in the heavy fermion strange metal YbRh$_2$Si$_2$ exhibit a strong suppression of the Fano factor ($F$) -- the ratio of the current noise to the average current in the DC limit. This system is representative of metals in which electron correlations are extremely strong. Here we carry out the first theoretical study on the shot noise of diffusive metals in the regime of strong correlations. A Boltzmann-Langevin equation formulation is constructed in a quasiparticle description in the presence of strong correlations. We find that $F = \sqrt{ 3}/{4}$ in such a correlation regime. Thus, we establish the aforementioned Fano factor as universal to Fermi liquids, and show that the Fano factor suppression observed in experiments on YbRh$_2$Si$_2$ necessitates a loss of the quasiparticles. Our work opens the door to systematic theoretical studies of shot noise as a means of characterizing strongly correlated metallic phases and materials.
