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arXiv · 2010.14400

Hall Effect for Dirac Electrons in Graphene Exposed to an Abrikosov Flux Lattice

Jonathan Schirmer·Ravi Kumar·Vivas Bagwe·Pratap Raychaudhuri·Takashi Taniguchi·Kenji Watanabe·C. -X. Liu·Anindya Das·J. K. Jain
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Abstract

The proposals for realizing exotic particles through coupling of quantum Hall effect to superconductivity involve spatially non-uniform magnetic fields. As a step toward that goal, we study, both theoretically and experimentally, a system of Dirac electrons exposed to an Abrikosov flux lattice. We theoretically find that non-uniform magnetic field causes a carrier-density dependent reduction of the Hall conductivity. Our studies show that this reduction originates from a rather subtle effect: a levitation of the Berry curvature within Landau levels broadened by the non-uniform magnetic field. Experimentally, we measure the magneto-transport in a monolayer graphene-hexagonal boron nitride - niobium diselenide (NbSe$_2$) heterostructure, and find a density-dependent reduction of the Hall resistivity of graphene as the temperature is lowered from above the superconducting critical temperature of NbSe$_2$, when the magnetic field is uniform, to below, where the magnetic field bunches into an Abrikosov flux lattice.

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Jonathan Schirmer, Ravi Kumar, Vivas Bagwe, Pratap Raychaudhuri, Takashi Taniguchi, Kenji Watanabe, C. -X. Liu, Anindya Das, J. K. Jain. 2020-10-27. Hall Effect for Dirac Electrons in Graphene Exposed to an Abrikosov Flux Lattice. https://doi.org/10.1209/0295-5075%2F132%2F37002

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