posted on 2023-12-11, 17:33authored byJinfeng Zhai, Mattia Trama, Hao Liu, Zhifei Zhu, Yinyan Zhu, Carmine Antonio Perroni, Roberta Citro, Pan He, Jian Shen
Two-dimensional
electron gas (2DEG) at oxide interfaces
exhibits
various exotic properties stemming from interfacial inversion and
symmetry breaking. In this work, we report large nonlinear transverse
conductivities in the LaAlO3/KTaO3 interface
2DEG under zero magnetic field. Skew scattering was
identified as the dominant origin based on the cubic scaling of nonlinear
transverse conductivity with linear longitudinal conductivity and
3-fold symmetry. Moreover, gate-tunable nonlinear transport 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 triplet 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.
Nonlinear transport offers a new pathway to probe the Berry curvature
at oxide interfaces and facilitates new applications in oxide nonlinear
electronics.