Realization of a spin wave switch based on the Spin-Transfer-Torque effect

TL;DR

This paper demonstrates a spin wave switch utilizing the Spin-Transfer-Torque and Spin-Hall-Effect, achieving a 20-fold increase in spin wave intensity through nonlinear frequency shifts when damping is overcompensated.

Contribution

It introduces a novel spin wave switch based on SHE-STT effect, exploiting nonlinear frequency shifts for efficient spin wave amplification.

Findings

Spin wave intensity increased by a factor of 20 with SHE-STT effect.

Nonlinear frequency shift occurs when damping is overcompensated.

The switch operates effectively at a specific working point.

Abstract

We investigate the amplification of externally excited spin waves via the Spin-Transfer-Torque (STT) effect in combination with the Spin-Hall-Effect (SHE) employing short current pulses. The results reveal that, in the case of an overcompensation of the spin wave damping, a strong nonlinear shift of the spin wave frequency spectrum occurs. In particular, this shift affects the spin wave amplification using the SHE-STT effect. In contrast, this effect allows for the realization of a spin wave switch. By determining the corresponding working point, an efficient spin wave excitation is only possible in the presence of the SHE-STT effect yielding an increased spin wave intensity of a factor of 20 compared to the absence of the SHE-STT effect.