Spontaneous Hall effects in the electron system at the SmTiO3/EuTiO3 interface

TL;DR

This study investigates the magnetotransport properties of SmTiO3/EuTiO3 heterostructures, revealing spontaneous Hall effects linked to interface-induced carriers and complex spin structures, with implications for topological phenomena in magnetic interfaces.

Contribution

It demonstrates that interface-induced carriers in SmTiO3/EuTiO3 heterostructures lead to spontaneous Hall effects, highlighting the role of interfaces in tuning topological magnetic phenomena.

Findings

Interface introduces ~3.9x10^14 cm^-2 carriers.

Presence of anomalous and topological Hall effects.

Temperature-dependent sign change of Hall effects.

Abstract

Magnetotransport and magnetism of epitaxial SmTiO3/EuTiO3 heterostructures grown by molecular beam epitaxy are investigated. It is shown that the polar discontinuity at the interface introduces ~ 3.9x10^14 cm^-2 carriers into the EuTiO3. The itinerant carriers exhibit two distinct contributions to the spontaneous Hall effect. The anomalous Hall effect appears despite a very small magnetization, indicating a non-collinear spin structure and the second contribution resembles a topological Hall effect. Qualitative differences exist in the temperature dependence of both Hall effects when compared to uniformly doped EuTiO3. In particular, the topological Hall effect contribution appears at higher temperatures and the anomalous Hall effect shows a sign change with temperature. The results suggest that interfaces can be used to tune topological phenomena in itinerant magnetic systems.