Thermoelectrical manipulation of nano-magnets

TL;DR

This paper introduces a device that uses thermoelectric heating to control magnetic states in nano-structures, enabling switchable magnetoresistance oscillations with tunable frequencies from DC to GHz.

Contribution

It presents a novel spin-thermo-electronic device that manipulates magnetic coupling via Joule heating to achieve reversible magnetic switching and oscillations.

Findings

Reversible control of magnetic exchange coupling using Joule heating.

Magnetoresistance oscillations with tunable frequencies from DC to GHz.

Potential applications in high-frequency magnetic devices.

Abstract

We propose a device that can operate as a magneto-resistive switch or oscillator. The device is based on a spin-thermo-electronic control of the exchange coupling of two strong ferromagnets through a weakly ferromagnetic spacer. We show that the local Joule heating due to a high concentration of current in a magnetic point contact or a nanopillar can be used to reversibly drive the weak ferromagnet through its Curie point and thereby exchange-decouple the strongly ferromagnetic layers, which have an antiparallel ground state. Such a spin-thermionic parallel-to-antiparallel switching causes magnetoresistance oscillations where the frequency can be controlled by proper biasing from essentially DC to GHz.