Disentangling spin-orbit coupling and local magnetism in a quasi-two-dimensional electron system
Year: 2019
Type: article
Abstract: Quantum interference between time-reversed electron paths in two dimensions (2D) leads to the well-known weak localization correction to resistance. If spin-orbit coupling is present, the resistance correction is negative, termed weak antilocalization (WAL). Here, we report the observation of WAL coexisting with exchange coupling between itinerant electrons and localized magnetic moments. We use low-temperature magnetotransport measurements to investigate the quasi-two-dimensional, high-electron-density interface formed between ${\mathrm{SrTiO}}_{3}$ and the antiferromagnetic Mott insulator ${\mathrm{NdTiO}}_{3}$. As the magnetic field angle is gradually tilted away from the sample normal, the data reveal the 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 ($22\phantom{\rule{0.16em}{0ex}}{\ensuremath{\mu}}_{B}$ on average), their magnetic anisotropy, and mutual coupling strength. This effect is expected to arise in other 2D magnetic materials systems.
Institution: University of Minnesota
Language: English
Subfield: Atomic and Molecular Physics, and Optics
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: green
Awards: G1155173873, G1880088558, University of Minnesota MRSEC, G3888246322, G3937871735, G4504108201, UNIVERSITY OF MINNESOTA CENTER FOR QUANTUM MATERIALS (CQM), G543814473, G5870279591, G612969457, NNCI: Midwest Nano Infrastructure Corrider (MINIC), G6952612929, G8713762821, G8848676574, G8876996369, G8929337198
OpenAlex ID: W2967215785