Transition from non Fermi Liquid Behavior to Landau Fermi Liquid Behavior Induced by Magnetic Fields

TL;DR

Applying a small magnetic field to strongly correlated Fermi systems at zero temperature induces a transition from non-Fermi liquid to Landau Fermi liquid behavior, with the effective mass diverging as the field approaches zero.

Contribution

This work demonstrates how magnetic fields can tune strongly correlated systems into Fermi liquid states and explains the divergence of effective mass near zero field.

Findings

Magnetic field induces Landau Fermi liquid behavior in strongly correlated systems.

Effective mass diverges as 1/√B when B approaches zero.

Restoration of strongly correlated regime at finite temperature T*∝√B.

Abstract

We show that a strongly correlated Fermi system with the fermion condensate, which exhibits strong deviations from Landau Fermi liquid behavior, is driven into the Landau Fermi liquid by applying a small magnetic field $B$ at temperature T=0. This field-induced Landau Fermi liquid behavior provides the constancy of the Kadowaki-Woods ratio. A reentrance into the strongly correlated regime is observed if the magnetic field $B$ decreases to zero, then the effective mass $M^*$ diverges as $M^*\propto 1/\sqrt{B}$. At finite temperatures, the strongly correlated regime is restored at some temperature $T^*\propto\sqrt{B}$. This behavior is of general form and takes place in both three dimensional and two dimensional strongly correlated systems. We demonstrate that the observed $1/\sqrt{B}$ divergence of the effective mass and other specific features of heavy-fermion metals are accounted for by our consideration.