Spin Insulatronics

TL;DR

This paper reviews recent advances in spin insulatronics, focusing on generating, detecting, and controlling pure spin currents in magnetic insulators for low-energy, high-frequency spin-based information technologies.

Contribution

It provides a comprehensive overview of the latest methods and findings in the generation and manipulation of pure spin currents in magnetic insulators, highlighting new interface phenomena.

Findings

Enhanced control of spin excitations in insulators

Efficient spin transfer across metal-insulator interfaces

Potential for low-dissipation spintronic devices

Abstract

Spin insulatronics covers efforts to generate, detect, control, and utilize high-fidelity pure spin currents and excitations inside magnetic insulators. Ultimately, the new findings may open doors for pure spin-based information and communication technologies. The aim is to replace moving charges with dynamical entities that utilize low-dissipation coherent and incoherent spin excitations in antiferromagnetic and ferromagnetic insulators. The ambition is that the new pure spin-based system will suffer reduced energy losses and operate at high frequencies. In magnetic insulators, there are no mobile charge carriers that can dissipate energy. Integration with conventional electronics is possible via interface exchange interactions and spin-orbit couplings. In this way, the free electrons in the metals couple to the localized spins in the magnetic insulators. In turn, these links facilitate spin-transfer torques and spin-orbit torques across metal-insulator interfaces and the associated phenomena of spin-pumping and charge-pumping. The interface couplings also connect the electron motion inside the metals with the spin fluctuations inside the magnetic insulators. These features imply that the system can enable unprecedented control of correlations resulting from the electron-magnon interactions. We review recent developments to realize electric and thermal generation, manipulation, detection, and control of pure spin information in insulators.