Voltage-Controlled Magnon Transistor via Tunning Interfacial Exchange Coupling

TL;DR

This paper demonstrates a voltage-controlled magnon transistor that modulates magnon transport via interfacial exchange coupling, using gate voltage to influence spin-magnon conversion efficiency in a Pt/YIG/Pt structure, achieving a 10% change ratio at room temperature.

Contribution

It introduces a novel magnon transistor that uses gate voltage to control magnon transport through interfacial exchange coupling modulation.

Findings

Achieved 10%/(MV/cm) efficiency change at 300 K.

Demonstrated control of magnon transport via gate voltage.

Realized a prototype magnon transistor based on MECD effect.

Abstract

Magnon transistors that can effectively regulate magnon transport by an electric field are desired for magnonics which aims to provide a Joule-heating free alternative to the conventional electronics owing to the electric neutrality of magnons (the key carriers of spin-angular momenta in the magnonics). However, also due to their electric neutrality, magnons have no access to directly interact with an electric field and it is thus difficult to manipulate magnon transport by voltages straightforwardly. Here, we demonstrated a gate voltage ($V_{\rm g}$) applied on a nonmagnetic metal/magnetic insulator (NM/MI) interface that bended the energy band of the MI and then modulated the possibility for conduction electrons in the NM to tunnel into the MI can consequently enhance or weaken the spin-magnon conversion efficiency at the interface. A voltage-controlled magnon transistor based on the magnon-mediated electric current drag (MECD) effect in a Pt/Y$_{\rm 3}$Fe$_{\rm 5}$O$_{\rm 12}$ (YIG)/Pt sandwich was then experimentally realized with $V_{\rm g}$ modulating the magnitude of the MECD signal. The obtained efficiency (the change ratio between the MECD voltage at $\pm V_{\rm g}$) reached 10%/(MV/cm) at 300 K. This prototype of magnon transistor offers an effective scheme to control magnon transport by a gate voltage.