Dirac points of electron energy spectrum, band-contact lines, and electron topological transitions of 3 1/2 kind in three-dimensional metals

TL;DR

This paper investigates Dirac points and band-contact lines in 3D metals with inversion symmetry, revealing how topological transitions of a specific kind affect electron spectra and magnetic susceptibility.

Contribution

It provides a detailed theoretical analysis of 3 1/2 order topological transitions caused by band-contact lines in metals with weak spin-orbit coupling.

Findings

Detection of topological transitions via giant diamagnetic anomalies

Identification of band-contact lines as key features in electron spectra

Theoretical characterization of 3 1/2 order transitions

Abstract

In many of three-dimensional metals with the inversion symmetry and a weak spin-orbit interaction, Dirac points of the electron energy spectrum form band-contact lines in the Brillouin zones of these crystals, and electron topological transitions of 3 1/2 kind are due to certain points of these lines. We theoretically study these transitions in detail, and point out that they can be detected with the magnetic susceptibility which exhibits a giant diamagnetic anomaly at the 3 1/2 -order transitions.