Influences of spin-orbit coupling on Fermi surfaces and Dirac cones in ferroelectric-like polar metals

TL;DR

This paper investigates how spin-orbit coupling affects the electronic structure of ferroelectric-like polar metals, revealing unique spin textures, Dirac cones, and potential applications in spintronics through first-principles and effective model analyses.

Contribution

It introduces the first detailed analysis of spin textures and Dirac cones in ferroelectric-like polar metals, highlighting effects of spin-orbit coupling and symmetry.

Findings

Spin textures are present on the Fermi surface.

Spin-momentum locking occurs at Dirac cones.

Dirac points are predicted in LiGaGe.

Abstract

Based on first-principles calculations and k .p effective models, we report physical properties of ferroelectric-like hexagonal polar metals with P63mc symmetry, which are distinct from those of conventional metals with spatial inversion symmetry. Spin textures exist on the Fermi surface of polar metals (e.g. ternary LiGaGe and elemental polar metal of Bi) and spin-momentum locking exist on accidental Dirac cones on the sixfold rotational axis, due to the spin-orbit coupling and lack of inversion symmetry in polar space group. This effect has potential applications in spin-orbitronics. Dirac points are also predicted in LiGaGe.