Surface Acoustic Wave induced modulation of tunneling magnetoresistance in magnetic tunnel junctions

TL;DR

This study demonstrates that surface acoustic waves can modulate the tunneling magnetoresistance in magnetic tunnel junctions by affecting their resistances without significantly altering magnetization, revealing insights into their dynamic behavior under strain.

Contribution

It is the first to show how surface acoustic waves influence tunneling magnetoresistance in MTJs without causing large magnetization rotations.

Findings

SAW decreases both parallel and antiparallel resistances, more so for antiparallel.

TMR ratio decreases under SAW application.

Magnetization coercivities remain largely unaffected.

Abstract

We show that a surface acoustic wave (SAW) applied across the terminals of a magnetic tunnel junction (MTJ) decreases both the (time-averaged) parallel and antiparallel resistances of the MTJ, with the latter decreasing much more than the former. This results in a decrease of the tunneling magnetoresistance (TMR) ratio. The coercivities of the free and fixed layer of the MTJ, however, are not affected significantly, suggesting that the SAW does not cause large-angle magnetization rotation in the magnetic layers through the inverse magnetostriction (Villari) effect at the power levels used. This study sheds light on the dynamical behavior of an MTJ under periodic compressive and tensile strain.