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arXiv · 1810.11751

Negative longitudinal magnetoresistance in GaAs quantum wells

Jing Xu·Meng K. Ma·Maksim Sultanov·Zhi-Li Xiao·Yong-Lei Wang·Dafei Jin·Yang-Yang Lyu·Wei Zhang·Loren N. Pfeiffer·Ken W. West·Kirk W. Baldwin·Mansour Shayegan·Wai-Kwong Kwok
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Abstract

Negative longitudinal magnetoresistances (NLMRs) have been recently observed in a variety of topological materials and often considered to be associated with Weyl fermions that have a defined chirality. Here we report NLMRs in non-Weyl GaAs quantum wells. In the absence of a magnetic field the quantum wells show a transition from semiconducting-like to metallic behaviour with decreasing temperature. We observed pronounced NLMRs up to 9 Tesla at temperatures above the transition and weak NLMRs in low magnetic fields at temperatures close to the transition and below 5 K. The observed NLMRs show various types of magnetic field behaviour resembling those reported in topological materials. We attribute them to microscopic disorder and use a phenomenological three-resistor model to account for their various features. Our results showcase a new contribution of microscopic disorder in the occurrence of novel phenomena. They may stimulate further work on tuning electronic properties via disorder/defect nano-engineering.

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Jing Xu, Meng K. Ma, Maksim Sultanov, Zhi-Li Xiao, Yong-Lei Wang, Dafei Jin, Yang-Yang Lyu, Wei Zhang, Loren N. Pfeiffer, Ken W. West, Kirk W. Baldwin, Mansour Shayegan, Wai-Kwong Kwok. 2018-10-28. Negative longitudinal magnetoresistance in GaAs quantum wells. https://doi.org/10.1038/s41467-018-08199-2

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