Ferromagnetic Proximity Induced Coupling and Exchange Splitting Effects in Graphene

ORAL

Abstract

Ferromagnet (FM)/2D material interface with broken symmetry is a potential avenue for new physics and to realize exchange field controllable future spintronics devices. Proximity-induced effects of a FM on TI and graphene (G) have been explored previously with EuS as the ferromagnet, inducing magnetic correlations in the adjacent layer [1]. Magnetic semiconductor GdN would enable higher temperature operation. We report successful sputter growth of ultrathin excellent GdN films on high-quality G synthesized on SiC substrate to form G/FM heterostructures. The properties of G are unperturbed with 15 nm thick GdN film grown over it, having a magnetic moment ≈ 7 μB and Curie temperature ≈ 33 K. Temperature-dependent Raman spectrum of electric field tunable GdN/G system shows a clear signature of graphene G peak near 1580 cm-1 and G’ peak near 2700 cm-1 confirming its quality. The induced magnetic correlations in G creating exchange gap in the Dirac surface states by GdN is investigated. Furthermore, patterning a superconductor over this bilayer for Josephson pair tunnelling studies in G will be presented.

[1] P Wei et al, PRL 110, 186807 (2013); Nat. Mat. 15, 711 (2016); Katmis et al Nature 533, 513 (2016)

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Presenters

  • Dhavala Suri

    Plasma Science and Fusion Center and Francis Bitter Magnet Laboratory, MIT, Francis Bitter Magnet Laboratory and Plasma Science and Fusion Center, MASSACHUSETTS INSTITUTE OF TECHNOLOGY

Authors

  • Dhavala Suri

    Plasma Science and Fusion Center and Francis Bitter Magnet Laboratory, MIT, Francis Bitter Magnet Laboratory and Plasma Science and Fusion Center, MASSACHUSETTS INSTITUTE OF TECHNOLOGY

  • Gregory Stephen

    Department of Physics, Northeastern University, Northeastern University

  • Wei Kong

    Department of Material Science and Engineering, MASSACHUSETTS INSTITUTE OF TECHNOLOGY, Massachusetts Institute of Technology

  • Mirko Rocci

    Dept. Of Physics, Plasma Science and Fusion Center and Francis Bitter Magnet Lab, Massachusetts Institute of Technology, Francis Bitter Magnet Laboratory and Plasma Science and Fusion Center, MASSACHUSETTS INSTITUTE OF TECHNOLOGY

  • Narendra Kumar

    Department of Physics, Boston College, Physics, Boston College

  • Yiping Wang

    Department of Physics, Boston College, Boston College

  • Kenneth Burch

    Department of Physics, Boston College, Boston College, Physics, Boston College

  • Jeehwan Kim

    Department of Material Science and Engineering, MASSACHUSETTS INSTITUTE OF TECHNOLOGY, Massachusetts Institute of Technology

  • Don Heiman

    Department of Physics, Northeastern University

  • Jagadeesh Moodera

    Dept. Of Physics, Plasma Science and Fusion Center and Francis Bitter Magnet Lab, Massachusetts Institute of Technology, MIT, Department of Physics, Massachusetts Institute of Technology, Massachusetts Institute of Technology, Department of Physics, Plasma Science and Fusion Center, and Francis Bitter Magnet Lab, Massachusetts Institute of Technology, Plasma Science and Fusion Center and Francis Bitter Magnet Laboratory, MIT, Plasma Science and Fusion Center, and Francis Bitter Magnet Laboratory, and Department of Physics, MIT, Francis Bitter Magnet Laboratory and Plasma Science and Fusion Center, MASSACHUSETTS INSTITUTE OF TECHNOLOGY, Plasma Science and Fusion Center and Francis Bitter Magnet Laboratory, Massachusetts Institute of Technology, Physics, Francis Bitter Magnet Laboratory, Plasma Science and Fusion Center, Massachusetts Institute of Technology, Department of Physics, MIT, Cambridge, MA, 02139