Fabrication of magnetic tunnel junctions connected through a continuous free layer to enable spin logic devices

TL;DR

This paper reports the first fabrication of interconnected magnetic tunnel junctions via a shared free layer, enabling spin logic devices like the spin torque majority gate with potential for future scalable spintronic logic circuits.

Contribution

It introduces a novel fabrication method for interconnected MTJs with a shared free layer, advancing spin logic device development.

Findings

Demonstrated independent biasing and magnetoelectric response of interconnected MTJs.

Achieved electrical control of devices, enabling domain wall motion for logic.

First fabrication of a cross-shaped free layer shared by multiple perpendicular MTJs.

Abstract

Magnetic tunnel junctions (MTJs) interconnected via a continuous ferromagnetic free layer were fabricated for Spin Torque Majority Gate (STMG) logic. The MTJs are biased independently and show magnetoelectric response under spin transfer torque. The electrical control of these devices paves the way to future spin logic devices based on domain wall (DW) motion. In particular, it is a significant step toward the realization of a majority gate, even though further downscaling may be required. To our knowledge, this is the first fabrication of a cross-shaped free layer shared by several perpendicular MTJs. The fabrication process can be generalized to any geometry and any number of MTJs. Thus, this framework can be applied to other spin logic concepts based on magnetic interconnect. Moreover, it allows exploration of spin dynamics for logic applications