Orientation dependent anomalous Hall and spin Hall currents at junctions of altermagnets with $p$-wave magnets

TL;DR

This paper investigates how junctions between altermagnets and p-wave magnets can generate and control transverse charge and spin currents through orientation-dependent effects, despite neither material being intrinsically spin-polarized.

Contribution

It introduces a continuum model showing finite transverse spin and charge currents at AM-PM junctions, highlighting the role of crystallographic orientation and momentum mode matching.

Findings

Transverse conductivities can be finite even when longitudinal conductivities vanish.

Transverse spin currents remain finite for certain orientations despite zero transverse charge conductivity.

Junctions enable tunable spin and charge current control based on orientation and spin structure.

Abstract

We study charge and spin transport across a junction between an altermagnet (AM) and a $p$-wave magnet (PM) using a continuum model with boundary conditions tailored to the spin-split band structures of the two materials. Remarkably, although neither AM nor PM is spin-polarized, we find that the junction supports finite spin currents both longitudinally and transversely. We compute the longitudinal and transverse charge and spin conductivities as functions of the crystallographic orientations and the relative angle between the N\'eel vectors of AM and PM. Our results reveal that transverse charge and spin conductivities can be finite even when the longitudinal charge conductivity vanishes. For suitable parameter choices and orientation angles, the transverse conductivities are more prominent than the longitudinal ones. The origin of these effects lies in the matching and mismatching of transverse momentum modes ($k_y$) across the junction combined with the spin-dependent band splitting in AM and PM. Furthermore, while the transverse charge conductivity may be zero for certain orientations, the transverse spin conductivity remains finite due to unequal contributions of opposite $k_y$ channels. These findings highlight AM-PM junctions as a promising platform for tunable generation and control of transverse charge and spin currents driven purely by crystallographic orientation and spin structure.