Inverse Tunneling Magnetoresistance in nanoscale Magnetic Tunnel Junctions

TL;DR

This paper presents a theoretical investigation of inverse TMR in nanoscale magnetic tunnel junctions, revealing a sign change in TMR with increasing transmission probability, relevant to junctions with pinholes or quantum point contacts.

Contribution

It demonstrates the conditions under which inverse TMR occurs in nanoscale magnetic tunnel junctions, especially near high transmission probabilities.

Findings

Positive TMR in weak tunneling limit

TMR sign reverses at high transmission close to unity

Relevance to junctions with pinholes or quantum point contacts

Abstract

We report on our theoretical study of the inverse TMR effect in the spin polarized transport through a narrow channel. In the weak tunneling limit, we find the ordinary positive TMR. The TMR changes its sign as the transmission probability becomes large close to a unity. Our results might be relevant to the magnetic tunnel junction with a pinhole or a quantum point contact.