Magnetoresistance of Highly Correlated Electron Liquid

TL;DR

This paper investigates the magnetoresistance behavior of a highly correlated electron liquid near a quantum phase transition, revealing temperature and magnetic field dependencies of effective mass and resistivity that influence MR sign changes.

Contribution

It introduces a detailed $T-B$ phase diagram showing how effective mass and resistivity behaviors affect magnetoresistance in correlated electron systems.

Findings

Effective mass depends on temperature as $T^{-1/2}$ at high T.

Resistivity exhibits non-Fermi liquid behavior, $ ho(T) o T$ and $ ho(T) o T^{3/2}$.

Magnetoresistance transitions from negative to positive with increasing temperature.

Abstract

The behavior in magnetic fields of a highly correlated electron liquid approaching the fermion condensation quantum phase transition from the disordered phase is considered. We show that at sufficiently high temperatures $T\geq T^*(x)$ the effective mass starts to depend on $T$, $M^*\propto T^{-1/2}$. This $T^{-1/2}$ dependence of the effective mass at elevated temperatures leads to the non-Fermi liquid behavior of the resistivity, $\rho(T)\propto T$ and at higher temperatures $\rho(T)\propto T^{3/2}$. The application of a magnetic field $B$ restores the common $T^2$ behavior of the resistivity. The effective mass depends on the magnetic field, $M^*(B)\propto B^{-2/3}$, being approximately independent of the temperature at $T\leq T^*(B)\propto B^{4/3}$. At $T\geq T^*(B)$, the $T^{-1/2}$ dependence of the effective mass is re-established. We demonstrate that this $B-T$ phase diagram has a strong impact on the magnetoresistance (MR) of the highly correlated electron liquid. The MR as a function of the temperature exhibits a transition from the negative values of MR at $T\to 0$ to the positive values at $T\propto B^{4/3}$. Thus, at $T\geq T^*(B)$, MR as a function of the temperature possesses a node at $T\propto B^{4/3}$.