Emergence of Topological Hall Effect in a SrRuO₃ Single Layer

Area of Science:

• Condensed Matter Physics
• Materials Science
• Spintronics

Background:

• Topological Hall effect (THE) is a key indicator of skyrmion spin textures, arising from broken inversion symmetry and spin-orbit interaction.
• Néel-type skyrmions were previously proposed in heterostructures like SrRuO3/SrIrO3 bilayers due to interfacial Dzyaloshinskii-Moriya interaction (DMI).

Purpose of the Study:

• To experimentally demonstrate the emergence of THE in SrRuO3 single layers.
• To investigate the influence of oxygen octahedron rotation on THE.
• To explore the tunability of THE by an applied electrical field.

Main Methods:

• Experimental synthesis of SrRuO3 single layers with thicknesses from 3 to 6 nm.
• Measurement of Hall resistance curves to identify THE.
• Application of electrical fields to tune the observed effects.

Main Results:

• The emergence of THE was experimentally demonstrated in SrRuO3 single layers.
• Oxygen octahedron rotation significantly affects the observed THE.
• THE was found to be continuously tunable by an applied electrical field.

Conclusions:

• The study proposes that strong spin-orbit coupling (SOC) in Ru ions and broken inversion symmetry at the interface generate the DMI responsible for THE in SrRuO3 single layers.
• The discovery of gate-tunable DMI in SrRuO3 single layers opens new possibilities for investigating spin-orbit physics in oxides.