The electronic structure of the heavy fermion metal $LiV_2O_4$

TL;DR

This paper investigates the electronic structure of LiV_2O_4, a heavy fermion compound without f-electrons, using ab-initio calculations and impurity models to understand its Kondo physics and coherence scale.

Contribution

It provides the first ab-initio analysis of LiV_2O_4's electronic structure and links the exhaustion phenomenon to the observed heavy-fermion behavior.

Findings

One electron of V is localized due to Coulomb interactions.

The Kondo energy scale T_K is estimated using the Anderson impurity model.

The coherence temperature T_{coh} is significantly reduced by exhaustion effects.

Abstract

The electronic structure of the first reported heavy fermion compound without f-electrons LiV_2O_4 was studied by an ab-initio calculation method. In the result of the trigonal splitting and d-d Coulomb interaction one electron of the $d^{1.5}$ configuration of V ion is localized and the rest partially fills a relatively broad conduction band. The effective Anderson impurity model was solved by Non-Crossing-Approximation method, leading to an estimation for the single-site Kondo energy scale T_K. Then, we show how the so-called exhaustion phenomenon of Nozi\`eres for the Kondo lattice leads to a remarkable decrease of the heavy-fermion (or coherence) energy scale $T_{coh}\equiv {T_K}^2/D$ (D is the typical bandwidth), comparable to the experimental result.