Control of magnetization dynamics by spin Nernst torque

TL;DR

This paper demonstrates the control of magnetization dynamics using spin Nernst torque in a Pt/Py bi-layer, providing an alternative method to manipulate nano-magnets through thermal gradients.

Contribution

It provides experimental evidence of magnetization control via spin Nernst torque and compares its strength to spin Hall torque in a Pt/Py system.

Findings

Spin Nernst torque can influence magnetization dynamics.

Systematic variation of magnetic linewidth shows the effect of thermal gradients.

Spin Nernst torque offers an alternative to charge current-based control.

Abstract

Control of magnetization dynamics is one of the primary goals in spintronics. It has been demonstrated using spin Hall effect i.e charge current to spin current conversion in non-magnetic metal which has large spin-orbit coupling such as Pt, W etc. Recently different groups have shown generation of spin current in Pt, W while thermal gradient is created by virtue of spin Nernst effect. In this work we show the evidence of magnetization control by spin Nernst torque in Pt/Py bi-layer. We compared relative strength of spin Nernst Torque and spin Hall torque by measuring the systematic variation of magnetic linewidth on application of constant heat or charge current. Spin-torque ferromagnetic resonance (ST-FMR) technique is adopted to excite the magnet and to measure line-width precisely from the symmetric and anti-symmetric voltage component. Control of magnetization dynamics by spin Nernst torque will emerge as an alternative way to manipulate nano-magnets.