Spin-orbit coupling and local magnetism at a complex oxide interface

SrTiO₃-based thin-film heterostructures are a powerful platform for studying a wide array of electronic phases in two dimensions, at high carrier densities. This talk will discuss low-temperature electronic transport studies of NdTiO₃/SrTiO₃ interfaces, which reveal local ferromagnetic order and strong spin-orbit interaction. As the magnetic field angle is gradually tilted away from the sample normal, the data reveals an intriguing interplay between strong k-cubic Rashba-type spin-orbit coupling and a substantial magnetic exchange interaction from local magnetic regions. The resulting quantum corrections to the conduction are in excellent agreement with existing models and allow sensitive determination of the small magnetic moments (22 µ_B on average), their magnetic anisotropy and mutual coupling strength. This effect is expected to arise in other 2D magnetic materials systems and could provide a simple yet powerful tool for investigating local magnetism.

Reference: Xinxin Cai, Yilikal Ayino, Jin Yue, Peng Xu, Bharat Jalan, and Vlad S. Pribiag, Phys. Rev. B 100, 081402(R) (2019).