Néel Skyrmion Bubbles in LaSrMnRuO Multilayers.

Ferromagnetic LaSrMnRuO epitaxial multilayers with controlled variation of the Ru/Mn content were synthesized to engineer canted magnetic anisotropy and variable exchange interactions, and to explore the possibility of generating a Dzyaloshinskii-Moriya interaction. The ultimate aim of the multilayer design is to provide the conditions for the formation of domains with nontrivial magnetic topology in an oxide thin film system. Employing magnetic force microscopy and Lorentz transmission electron microscopy in varying perpendicular magnetic fields, magnetic stripe domains separated by Néel-type domain walls as well as Néel skyrmions smaller than 100 nm in diameter were observed.

Electronic Inhomogeneity Influence on the Anomalous Hall Resistivity Loops of SrRuO Epitaxially Interfaced with 5d Perovskites.

SrRuO, a 4d ferromagnet with multiple Weyl nodes at the Fermi level, offers a rich playground to design epitaxial heterostructures and superlattices with fascinating magnetic and magnetotransport properties. Interfacing ultrathin SrRuO layers with large spin-orbit coupling 5d transition-metal oxides, such as SrIrO, results in pronounced peaklike anomalies in the magnetic field dependence of the Hall resistivity. Such anomalies have been attributed either to the formation of Néel-type skyrmions or to modifications of the Berry curvature of the topologically nontrivial conduction bands near the Fermi level of SrRuO.

Direct Probing of Polarization Charge at Nanoscale Level.

Ferroelectric materials possess spontaneous polarization that can be used for multiple applications. Owing to a long-term development of reducing the sizes of devices, the preparation of ferroelectric materials and devices is entering the nanometer-scale regime. Accordingly, to evaluate the ferroelectricity, there is a need to investigate the polarization charge at the nanoscale.

Impact of interfacial coupling of oxygen octahedra on ferromagnetic order in LaSrMnO/SrTiO heterostructures.

LaSrMnO, a half-metallic ferromagnet with full spin polarization, is generally used as a standard spin injector in heterostructures. However, the magnetism of LaSrMnO is strongly modified near interfaces, which was addressed as "dead-layer" phenomenon whose origin is still controversial. Here, both magnetic and structural properties of LaSrMnO/SrTiO heterostructures were investigated, with emphasis on the quantitative analysis of oxygen octahedral rotation (OOR) across interfaces using annular-bright-field imaging.