Ferromagnetism of Weakly-Interacting Electrons in Disordered Systems
Abstract
It was realized two decades ago that the two-dimensional diffusive Fermi liquid phase is unstable against arbitrarily weak electron-electron interactions. Recently, using the nonlinear sigma model developed by Finkelstein, several authors have shown that the instability leads to a ferromagnetic state. In this paper, we consider diffusing electrons interacting through a ferromagnetic exchange interaction. Using the Hartree-Fock approximation to directly calculate the electron self energy, we find that the total energy is minimized by a finite ferromagnetic moment for arbitrarily weak interactions in two dimensions and for interaction strengths exceeding a critical proportional to the conductivity in three dimensions. We discuss the relation between our results and previous ones.
Keywords
Cite
@article{arxiv.cond-mat/0501431,
title = {Ferromagnetism of Weakly-Interacting Electrons in Disordered Systems},
author = {Xiao Yang and Chetan Nayak},
journal= {arXiv preprint arXiv:cond-mat/0501431},
year = {2009}
}