Metallic characteristics in superlattices composed of insulators, NdMnO3/SrMnO3/LaMnO3

TL;DR

This study investigates the electronic and magnetic properties of superlattices made from antiferromagnetic insulators NdMnO3, SrMnO3, and LaMnO3, revealing emergent metallic behavior and spin-charge correlations at their interfaces.

Contribution

It provides new insights into the metallic characteristics and spin-charge interactions in complex oxide superlattices composed of insulating antiferromagnets.

Findings

Observation of metallic behavior via Fermi cut-off in photoemission spectra.

Correlation between magnetization and density of states near Fermi energy.

Metallic properties primarily originate from Mn e_g electrons.

Abstract

We report on the electronic properties of superlattices composed of three different antiferromagnetic insulators, NdMnO3/SrMnO3/LaMnO3 grown on SrTiO3 substrates. Photoemission spectra obtained by tuning the x-ray energy at the Mn 2p -> 3d edge show a Fermi cut-off, indicating metallic behavior mainly originating from Mn e_g electrons. Furthermore, the density of states near the Fermi energy and the magnetization obey a similar temperature dependence, suggesting a correlation between the spin and charge degrees of freedom at the interfaces of these oxides.