Non-Fermi Liquids in a Generalized Anderson Model

Rok Žitko, J. Bonča

Anamitra Mukherjee, Niravkumar D. Patel, Nitin Kaushal +2 more

Qimiao Si A, Gabriel Kotliar

We study an extended Hubbard model in the limit of infinite dimensions. The local correlation functions of this model are those of a generalized asymmetric Anderson model. The impurity model displays a Fermi liquid phase, a phase with neither the spin nor the charge of the impurity quenched, and an intermediate phase with the spin but not the charge of the impurity quenched. This analysis establishes the existence of metallic non-Fermi-liquid phases of the lattice model over a wide range of parameters and electron densities. The non-Fermi-liquid phases describe metals with incoherent spin and/or charge excitations and self-similar local correlation functions.

Patrick O’Brien

Lan Zhang, Yin Zhong, Hong‐Gang Luo

We investigate a modified Anderson model at the large-N limit, where the Coulomb interaction is replaced by the Sachdev–Ye–Kitaev random interaction. The resistivity of conduction electron ρ c has a minimum value around temperature T*, which is similar to the Kondo system, but the impurity electron’s density of state A d(ω) demonstrates no sharp-peak like the Kondo resonance around the Fermi surface. This provides a counterintuitive example where resistivity minimum exists without Kondo resonance. The impurity electron’s entropy S d and specific heat capacity C v show a crossover from Fermi liquid to a non-Fermi liquid behavior dependent on temperature. The system is a Fermi liquid at T < T*, and becomes a non-Fermi liquid at T > T*, and then becomes a Fermi gas at sufficiently high temperatures T ≫ T*. The non-Fermi liquid at the intermediate-T regime does not occur in the standard Anderson model. We also make a renormalization group analysis, which confirms the crossover from Fermi liquid to the non-Fermi behavior. It is emphasized that the resistivity minimum emerges in our model when the system behaves as a non-Fermi liquid rather than Fermi liquid, which provides an alternative example showing resistivity minimum in condensed matter physics.

Subhro Bhattacharjee, Sung-Sik Lee, Yong Baek Kim