Orbital-Zeeman cross correlation in $p$- and $d$-wave altermagnets

TL;DR

This paper investigates the orbital-Zeeman cross term in altermagnets, focusing on Rashba metals and topological insulator surfaces, revealing how different order parameters influence the OZ term's behavior and magnitude.

Contribution

It introduces the study of the orbital-Zeeman cross term in altermagnets, analyzing effects of p- and d-wave order parameters on Rashba metals and TI surfaces.

Findings

d-wave order causes sign change in OZ term at large magnitude

p-wave order retains step-function dependence but reduces magnitude

d-wave case preserves jump magnitude but decreases OZ with increasing chemical potential

Abstract

Altermagnets are a novel class of magnets that exhibit a large spin splitting but the total magnetic moment is vanishing. This unconventional spin splitting gives rise to various characteristic phenomena, such as spin current generation. In this paper, we study the orbital-Zeeman (OZ) cross term in altermagnets. Specifically, we consider the Rashba metal and the surface Dirac cones of three-dimensional topological insulators (TIs) in the presence of the altermagnetic order parameters. For the Rashba metals, the $p$-wave order parameter exerts only a limited influence on the OZ term, whereas the $d$-wave one causes the sign change of it when the order parameter becomes sufficiently large. For the TI surface, the $p$-wave order parameter retains the step-function-type dependence of the OZ term as a function of the chemical potential ($\mu$) associated with the jump at $\mu=0$, observed in the TI surface without magnetism, but its magnitude is reduced. For the $d$-wave case, the magnitude of jump at $\mu =0$ is preserved but the OZ term decreases as increasing $|\mu|$.