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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 SrTiO3 and the antiferromagnetic Mott insulator NdTiO3. 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 (22μB on average), their magnetic anisotropy, and mutual coupling strength. This effect is expected to arise in other 2D magnetic materials systems.
Bibliographical noteFunding Information:
We thank Z. Jiang and B. Yang for assistance with PPMS measurements, and P. Crowell, L. Zhao, and Y. Iguchi for valuable discussions. This work was supported primarily by the Office of Naval Research under Award No. N00014-17-1-2884. Film growth and structural characterizations were funded by the U.S. Department of Energy through the University of Minnesota Center for Quantum Materials, under Grant No. DE-SC-0016371. Portions of this work were conducted in the Minnesota Nano Center, which is supported by the National Science Foundation through the National Nano Coordinated Infrastructure Network (NNCI) under Award No. ECCS-1542202. Sample structural characterization was carried out at the University of Minnesota Characterization Facility, which receives partial support from NSF through the MRSEC program under Award No. DMR-1420013.
© 2019 American Physical Society.
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Reporting period for MRSEC
- Period 6
11/1/14 → …
Project: Research project