Fermi-liquid theory for the single-impurity Anderson model
Fermi-liquid theory for the single-impurity Anderson model
复制标题
DOI：
10.1103/physrevb.92.075120
复制
发表时间：
2015-08-10
影响因子：
3.7
通讯作者：
Zarand, Gergely
中科院分区：
文献类型：
--
作者：
Mora, Christophe;Moca, Catalin Pascu;Zarand, Gergely
本文将Nozieres的费米液体理论推广到单杂质安德森模型。除了电子在费米能下的相移，低能费米液体理论还有四个费米液体参数：两个由Nozieres给出的进入一阶激发能的费米液体参数，以及另外两个进入二阶激发能的费米液体参数，它们需要远离粒子-空穴对称性。我们表示所有四个参数的零温度的物理观测量，即当地的电荷和自旋的磁化率和它们的衍生物相对于当地的水平位置。我们确定这些裸参数的安德森模型使用Bethe anterior和数值重整化群（NRG）计算。我们的低能费米液体理论适用于整个交叉从强耦合近藤政权通过混合价政权的空轨道政权。从费米液体理论出发，在小磁场、低温、小偏压条件下，确定了量子点通过对称耦合双引线的电导，并精确地根据费米液体参数计算了类B-2项、类T-2项和类V-2项的系数.发现T-2、V-2和B-2的系数在近藤到空轨道交叉期间改变符号。当局域相互作用远大于能级宽度时，这种交叉是普遍存在的。为了完整性，我们还计算散粒噪声，并讨论由此产生的Fano因子。
We generalize Nozieres' Fermi-liquid theory for the low-energy behavior of the Kondo model to that of the single-impurity Anderson model. In addition to the electrons' phase shift at the Fermi energy, the low-energy Fermi-liquid theory is characterized by four Fermi-liquid parameters: the two given by Nozieres that enter to first order in the excitation energy, and two additional ones that enter to second order and are needed away from particle-hole symmetry. We express all four parameters in terms of zero-temperature physical observables, namely the local charge and spin susceptibilities and their derivatives with respect to the local level position. We determine these in terms of the bare parameters of the Anderson model using Bethe ansatz and numerical renormalization group (NRG) calculations. Our low-energy Fermi-liquid theory applies throughout the crossover from the strong-coupling Kondo regime via the mixed-valence regime to the empty-orbital regime. From the Fermi-liquid theory, we determine the conductance through a quantum dot symmetrically coupled to two leads in the regime of small magnetic field, low temperature, and small bias voltage, and compute the coefficients of the similar to B-2, similar to T-2, and similar to V-2 terms exactly in terms of the Fermi-liquid parameters. The coefficients of T-2, V-2, and B-2 are found to change sign during the Kondo to empty-orbital crossover. The crossover becomes universal in the limit that the local interaction is much larger than the level width. For completeness, we also compute the shot noise and discuss the resulting Fano factor.