Negative longitudinal magnetoresistance in GaAs quantum wells
ORAL
Abstract
Negative longitudinal magnetoresistances (NLMRs) have been observed in a variety of materials and often considered to be associated with Weyl fermions that have a defined chirality. We conducted magnetotransport measurements and observed NLMRs in non-Weyl GaAs quantum wells. We observed pronounced NLMRs up to 9 Tesla at temperatures above the transition temperature and also weak NLMRs at low magnetic fields at temperatures close to the transition and at very low temperatures. The observed NLMRs show various types of magnetic field behavior, the origin of which we attribute to microscopic disorder and we use a phenomenological model to account for the various features. Our results showcase a new contribution of microscopic disorder to the occurrence of novel phenomena. They may stimulate further work on tuning electronic properties via disorder/defect nano-engineering.
*Sample fabrication and characterization were supported by the DOE Basic Energy Sciences (Grant No. DE-FG02-00-ER45841), the NSF (Grants No. DMR 1709076 and MRSEC DMR 1420541), and the GBMF (Grant No. GBMF4420). W. Z. acknowledges support from the DOE and NSF under Grants No. DMR-1808892. M. Su. was supported by the Fulbright Program. J. X. and Z. X. also acknowledge support by the NSF under Grant No. DMR-1407175.
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Presenters
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Jing Xu
- Northern Illinois University
- Materials Science Division, Argonne National Laboratory
- Argonne National Lab