Large nonlinear Hall effect and Berry curvature in KTaO3 based two-dimensional electron gas

Abstract

The two-dimensional electron gas (2DEG) at oxide interfaces exhibits various exotic properties stemming from interfacial inversion symmetry breaking. In this work, we report the emergence of large nonlinear Hall effects (NHE) in the LaAlO3/KTaO3(111) interface 2DEG under zero magnetic field. Skew scattering was identified as the dominant origin based on the cubic scaling of nonlinear Hall conductivity with longitudinal conductivity and the threefold symmetry. Moreover, a gate-tunable NHE with pronounced peak and dip was observed and reproduced by our theoretical calculation. These results indicate the presence of Berry curvature hotspots and thus a large Berry curvature triple at the oxide interface. Our theoretical calculations confirm the existence of large Berry curvatures from the avoided crossing of multiple 5d-orbit bands, orders of magnitude larger than that in transition-metal dichalcogenides. NHE offers a new pathway to probe the Berry curvature at oxide interfaces, and facilitates new applications in oxide nonlinear electronics.

References in corpus (7)

• Magnetic effects at the interface between nonmagnetic oxides
• Electric Field Control of the LaAlO${}_3$/SrTiO${}_3$ Interface Ground State
• Highly efficient and tuneable spin-to-charge conversion through Rashba coupling at oxide interfaces
• Nonlinear planar Hall effect
• Quantum frequency doubling in the topological insulator Bi2Se3
• Band Structure and Spin-Orbital Texture of the (111)-KTaO3 Two-Dimensional Electron Gas
• Artificial oxide heterostructures with non-trivial topology

Cited by in corpus (6)

• Non-linear Transport in Non-centrosymmetric Systems: From Fundamentals to Applications
• Non-linear anomalous Edelstein response at altermagnetic interfaces
• Edelstein Effect in Isotropic and Anisotropic Rashba Models
• Orbital and Spin Edelstein Effects in KTaO${}_3$(110) Two-Dimensional Electron Gases
• Boltzmann theory of the inverse Edelstein effect in a two-dimensional Rashba gas
• Quantum theory of nonlinear electromagnetic response