Orbital Magnetism of Bloch Electrons II. Application to Single-Band Models and Corrections to Landau-Peierls susceptibility

TL;DR

This paper calculates the orbital susceptibility of Bloch electrons in single-band models, revealing additional contributions beyond the Landau-Peierls term and highlighting limitations of the Peierls phase approximation.

Contribution

It extends the theory of orbital susceptibility to include first-order overlap integrals in single-band models on 2D lattices, providing new insights into magnetic response contributions.

Findings

Orbital susceptibility includes Fermi surface and intraband atomic diamagnetism contributions.

Peierls phase approximation is insufficient for magnetic field effects.

First-order overlap integrals significantly affect susceptibility calculations.

Abstract

Orbital susceptibility for Bloch electrons is calculated for the first time up to the first order with respect to overlap integrals between the neighboring atomic orbitals, assuming single-band models. A general and rigorous theory of orbital susceptibility developed in the preceding paper is applied to single-band models in two-dimensional square and triangular lattices. In addition to the Landau-Peierls orbital susceptibility, it is found that there are comparable contributions from the Fermi surface and from the occupied states in the partially filled band called intraband atomic diamagnetism. This result means that the Peierls phase used in tight-binding models is insufficient as the effect of magnetic field.