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arXiv · 1905.05952

Strain-Fluctuation-Induced Near-Quantization of Valley Hall Conductivity in Graphene Systems

Wen-Yu Shan·Di Xiao
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Abstract

We develop a theory of the valley Hall effect in high-quality graphene samples, in which strain fluctuation-induced random gauge potentials have been suggested as the dominant source of disorder. We find a near-quantized value of valley Hall conductivity in the band transport regime, which originates from an enhanced side jump of a Dirac electron when it scatters off the gauge potential. By assuming a small residue charge density our theory reproduces qualitatively the temperature- and gap-dependence of the observed valley Hall effect at the charge neutral point. Our study suggests that the valley Hall effect in graphene systems represents a new paradigm for the anomalous Hall physics where gauge disorder plays an important role.

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Wen-Yu Shan, Di Xiao. 2019-05-15. Strain-Fluctuation-Induced Near-Quantization of Valley Hall Conductivity in Graphene Systems. https://doi.org/10.1103/physrevb.99.205416

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