THz spectroscopy of graphene coupled to LaAlO3/SrTiO3 nanoscale junctions

ORAL

Abstract



We investigate the gate-dependent optical response of graphene using the broadband nonlinear generation and detection capabilities of nanoscale junctions created at the LaAlO3/SrTiO3 interface [1]. Using the large non-resonant third-order nonlinear susceptibility in SrTiO3, strong difference frequency mixing occurs when the junction is biased, leading to induced polarization that can also be detected at the junction [2]. Here we discuss results of gate-dependent experiments which interrogate the relationship between the THz signal and the gate location with respect to the Dirac point in devices where graphene is coupled to the LaAlO3/SrTiO3 interface. Preliminary results suggest we may be detecting a surface plasmon resonance or phonon mode. We will also discuss results indicating a gate-dependent enhancement of the graphene absorption.

[1] C. Cen, et al., Nature Materials 7, 298 (2008).
[2] Y. Ma, et al.,, Nano Lett 13, 2884 (2013).

*JL acknowledges support from a Vannevar Bush Faculty Fellowship, funded by ONR (N00014-15-1-2847), and ONR (N00014-16-1-3152) (JL). C-BE acknowledges support from AFOSR (FA9550-15-1-0334), NSF DMREF (DMR-1629270), and NSF MRSEC (DMR-1420645) (C-BE). ES acknowledges support from the NSF GRFP (1747452).

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Presenters

  • Erin Sutton

    • University of Pittsburgh

Authors

  • Erin Sutton

    • University of Pittsburgh

  • Lu Chen

    • Department of Physics and Astronomy, University of Pittsburgh
    • University of Pittsburgh

  • Jianan Li

    • Department of Physics and Astronomy, University of Pittsburgh
    • Department of Physics, University of Pittsburgh
    • University of Pittsburgh
    • Department of Physics & Astronomy, University of Pittsburgh
    • Physics and Astronomy, University of Pittsburgh

  • Qing Guo

    • Department of Physics and Astronomy, University of Pittsburgh
    • University of Pittsburgh

  • Hyungwoo Lee

    • Department of Materials Science and Engineering, University of Wisconsin–Madison
    • Department of Materials Science and Engineering, University of Wisconsin-Madison
    • University of Wisconsin-Madison
    • Department of Material Science and Engineering, University of Wisconsin-Madison
    • Materials Science and Engineering, University of Wisconsin-Madison
    • Materials Science and Engineering, Univ of Wisconsin-Madison
    • University of Wisconsin–Madison

  • Jungwoo Lee

    • Department of Materials Science and Engineering, University of Wisconsin-Madison
    • University of Wisconsin-Madison
    • Department of Materials Science and Engineering, University of Wisconsin–Madison
    • Department of Material Science and Engineering, University of Wisconsin-Madison
    • Materials Science and Engineering, University of Wisconsin-Madison
    • Materials Science and Engineering, Univ of Wisconsin-Madison

  • Chang-Beom Eom

    • Department of Materials Science and Engineering, University of Wisconsin–Madison
    • Department of Materials Science and Engineering, University of Wisconsin-Madison
    • University of Wisconsin-Madison
    • Department of Material Science and Engineering, University of Wisconsin-Madison
    • Materials Science and Engineering, University of Wisconsin-Madison
    • Materials Science and Engineering, Univ of Wisconsin-Madison
    • University of Wisconsin–Madison

  • Patrick Irvin

    • Department of Physics and Astronomy, University of Pittsburgh
    • Department of Physics, University of Pittsburgh
    • University of Pittsburgh
    • Department of Physics & Astronomy, University of Pittsburgh
    • Physics and Astronomy, University of Pittsburgh

  • Jeremy Levy

    • Department of Physics and Astronomy, University of Pittsburgh
    • Department of Physics, University of Pittsburgh
    • University of Pittsburgh
    • Department of Physics & Astronomy, University of Pittsburgh
    • Physics and Astronomy, University of Pittsburgh