Giant enhancement of anomalous Hall effect in Cr modulation-doped non-collinear antiferromagnetic Mn3Sn thin films

TL;DR

This study demonstrates that Cr doping in Mn3Sn thin films significantly enhances the anomalous Hall effect, especially in modulation-doped samples at low temperatures, due to Fermi level shifts.

Contribution

It reveals that low-concentration Cr doping can greatly increase anomalous Hall conductivity in Mn3Sn films without altering their structure or magnetism.

Findings

Cr doping enhances anomalous Hall conductivity

Modulation doping yields higher Hall conductivity at low temperatures

Fermi level shift explains the enhancement

Abstract

We report on Cr doping effect in Mn3Sn polycrystalline films with both uniform and modulation doping. It is found that Cr doping with low concentration does not cause notable changes to the structural and magnetic properties of Mn3Sn, but it significantly enhances the anomalous Hall conductivity, particularly for modulation-doped samples at low temperature. A Hall conductivity as high as 184.8 {\Omega}-1 cm-1 is obtained for modulation-doped samples at 50 K, in a sharp contrast to vanishingly small values for undoped samples at the same temperature. We attribute the enhancement to the change of Fermi level induced by Cr doping