Quenching of Impurity Spins at Cu/CuO Interfaces: An Antiferromagnetic Proximity Effect

TL;DR

This paper investigates how antiferromagnetic proximity effects at Cu/CuO interfaces suppress impurity spin quenching, revealing unique magnetoconductance features and spin dynamics in bilayer films.

Contribution

It demonstrates the suppression of magnetic impurity spin-flip scattering in Cu/CuO bilayers due to antiferromagnetic proximity effects, supported by weak antilocalization analysis.

Findings

Suppressed spin-flip scattering in Cu/CuO bilayers

Evidence of antiferromagnetic proximity effect

Slow spin relaxation below 1 K consistent with spin glass behavior

Abstract

It is observed that the magnetoconductance of bilayer films of copper (Cu) and copper monoxide (CuO) has distinct features compared of that of Cu films on conventional band insulator substrates. We analyze the data above 2 K by the theory of weak antilocalization in two-dimensional metals and suggest that spin-flip scatterings by magnetic impurities inside Cu are suppressed in Cu/CuO samples. Plausibly the results imply a proximity effect of antiferromagnetism inside the Cu layer, which can be understood in the framework of Ruderman-Kittel-Kasuya-Yoshida (RKKY) interactions. The data below 1 K, which exhibit slow relaxation reminiscent of spin glass, are consistent with this interpretation.