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)

*Funding Acknowledgement: NSF (DMR 1700137) and CIQM (DMR-1231319).

–

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