Spin Current Generation Controlled by the N\'{e}el State in a Compensated Ferrimagnet

TL;DR

This paper demonstrates that compensated ferrimagnets can generate and control spin currents via the Néel state, with potential applications in spintronic memory devices, by analyzing spin Seebeck effect and spin pumping.

Contribution

It reveals how isotropic spin splitting in compensated ferrimagnets influences spin transport and introduces spin pumping as a readout mechanism for their Néel states.

Findings

Sizable spin Seebeck signals with switchable sign by Néel state.

Néel-state-dependent resonance splitting in spin pumping.

Potential for magnetization-free spintronic memory devices.

Abstract

Compensated ferrimagnets, which break sublattice and time-reversal symmetries in the ground state, exhibit an isotropic ferromagnet-like spin splitting despite a vanishing net magnetization, in contrast to altermagnets with momentum-dependent spin splitting. We investigate how isotropic spin splitting manifests in spin transport by analyzing the spin Seebeck effect and spin pumping in a junction between a compensated ferrimagnet and a normal metal. We show that compensated ferrimagnets generate a sizable spin Seebeck signal, with a sign that can be reversed by switching between the two N\'{e}el states. Furthermore, we demonstrate that spin pumping exhibits a N\'{e}el-state-dependent resonance splitting, which is absent in conventional antiferromagnets. These results identify spin pumping as a natural readout mechanism for compensated ferrimagnets and establish them as promising magnetization-free building blocks for spintronic memory devices.