Huge tunnelling anisotropic magnetoresistance in (Ga,Mn)As nanoconstrictions

TL;DR

This study demonstrates extremely large tunnelling anisotropic magnetoresistance (TAMR) effects in (Ga,Mn)As nanoconstrictions, revealing potential for spintronic applications and advancing understanding of magnetotransport in ferromagnetic semiconductors.

Contribution

The paper reports the first observation of giant TAMR effects in (Ga,Mn)As nanoconstrictions, highlighting Coulomb blockade as the underlying mechanism.

Findings

TAMR up to 1300% observed in (Ga,Mn)As nanoconstrictions

Presence of multistable telegraphic switching behavior

Results support Coulomb blockade AMR mechanism

Abstract

We report large anisotropic magnetoresistance (AMR) behaviours in single lateral (Ga,Mn)As nanoconstriction of up to 1300%, along with large multistable telegraphic switching. The nanoconstriction devices are fabricated using high-resolution electron beam lithography of a 5 nm thick (Ga,Mn)As epilayer. The unusual behaviour exhibited by these devices is discussed in the context of existing theories for enhanced AMR ferromagnetic semiconductor nanoscale devices, particularly with regard to the dependence on the magnetotransport of the bulk material. We conclude that our results are most consistent with the Coulomb blockade AMR mechanism.