Quantum effects for ballistic transport in spintronic devices

TL;DR

This paper investigates quantum effects in spintronic devices with atomic-scale precision, revealing potential for giant magnetoresistance enhancements through quantum tunneling and resonant effects.

Contribution

It introduces a tight-binding quantum model for spintronic multilayers and suggests a method to achieve large magnetoresistance via gate-controlled resonances.

Findings

Quantum conduction modeled with tight-binding dynamics.

Resonant enhancement of magnetoresistance possible.

Gate voltage can tune quantum effects for improved device performance.

Abstract

Recent fabrication of atomic precision nanodevices for spintronics greatly boosted their performance and also revealed new interesting features, as oscillating magnetoresistance with number of atomic layers in a multilayered structure. This motivates the need to go beyond the usual theoretical approach of semi-classical continuous layers. Here the simple tight-binding dynamics is used to describe quantum conduction in a multicomponent system with spin-polarized electrodes separated by an ultrathin and atomically coherent non-magnetic spacer (either metallic or insulating). A possibility is indicated for obtaining a huge resonant enhancement of magnetoresistance in such device by a special choice of gate voltage on the spacer element.