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

• Published in: arXiv.org
• Main Authors: Schirmer, Jonathan, Kumar, Ravi, Vivas Bagwe, Raychaudhuri, Pratap, Taniguchi, Takashi, Watanabe, Kenji, Liu, C -X, Das, Anindya, Jain, J K
• Format: Paper Journal Article
• Language: English
• Published: Ithaca Cornell University Library, arXiv.org 28.10.2020
• Subjects: Boron nitride; Carrier density; Electromagnetism; Electrons; Flux; Graphene; Heterostructures; Levitation; Magnetic fields; Magnetism; Niobium; Nonuniform magnetic fields; Physics - Mesoscale and Nanoscale Physics; Quantum Hall effect; Reduction; Superconductivity
• ISSN: 2331-8422
• DOI: 10.48550/arxiv.2010.14400

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.