Quantum Correction to Conductivity Close to Ferromagnetic Quantum Critical Point in Two Dimensions

TL;DR

This paper investigates how quantum interference affects the temperature-dependent conductivity in a two-dimensional disordered electron system near a ferromagnetic quantum critical point, revealing a crossover temperature and a unique T^{1/3} behavior.

Contribution

It provides a detailed analysis of quantum interference effects near a ferromagnetic quantum critical point, highlighting a crossover temperature and a novel T^{1/3} conductivity dependence.

Findings

Crossover between diffusive and ballistic regimes occurs at T* = 1/τγ(E_Fτ)^2.

In the ballistic quantum critical regime, conductivity scales as T^{1/3}.

T* is generally smaller than 1/τ for typical parameters.

Abstract

We study the temperature dependence of the conductivity due to quantum interference processes for a two-dimensional disordered itinerant electron system close to a ferromagnetic quantum critical point. Near the quantum critical point, the cross-over between diffusive and ballistic regimes of quantum interference effects occurs at a temperature $ T^{\ast}=1/\tau \gamma (E_{F}\tau)^{2}$, where $\gamma $ is the parameter associated with the Landau damping of the spin fluctuations, $\tau $ is the impurity scattering time, and $E_{F}$ is the Fermi energy. For a generic choice of parameters, $T^{\ast}$ is smaller than the nominal crossover scale $1/\tau $. In the ballistic quantum critical regime, the conductivity behaves as $T^{1/3}$.