Charge transport and magnetization profile at the interface between the correlated metalCaRuO3and the antiferromagnetic insulatorCaMnO3

Abstract

A combination of spectroscopic probes was used to develop a detailed experimental description of the transport and magnetic properties of superlattices composed of the paramagnetic metal ${\text{CaRuO}}_3$ and the antiferromagnetic insulator ${\text{CaMnO}}_3$. The charge-carrier density and Ru valence state in the superlattices are not significantly different from those of bulk ${\text{CaRuO}}_3$. The small charge transfer across the interface implied by these observations confirms predictions derived from density-functional calculations. However, a ferromagnetic polarization due to canted Mn spins penetrates 3–4 unit cells into ${\text{CaMnO}}_3$, far exceeding the corresponding predictions. The discrepancy may indicate the formation of magnetic polarons at the interface.