THz spectroscopy of graphene and graphene nanoribbons using LaAlO<sub>3</sub>/SrTiO<sub>3</sub> nanoscale junctions

ORAL

Abstract


We investigate the optical response of graphene and graphene nanoribbons using the broadband nonlinear generation and detection capabilities of nanoscale junctions created at the LaAlO3/SrTiO3 interface [1]. Using the large 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 [2,3]. Here we discuss the results of 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. Results show near-100% extinction of VIS-NIR light in graphene, and suggest we may be detecting a surface plasmon resonance. Additional results on individual graphene nanoribbons reinforce this interpretation.
[1] C. Cen, et al., Nature Mat. 7, 298 (2008).
[2] Y. Ma, et al., Nano Lett 13, 2884 (2013).
[3] L. Chen, et al., Light: Sci. & Appl. 8, 24 (2019).

*J.Levy acknowledges a Vannevar Bush Faculty Fellowship (ONR N00014-15-1-2847), and the Office of Naval Research (N00014-16-1-3152). 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 NSF GRFP (1747452).

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Presenters

  • Erin Sheridan

    • Physics & Astronomy, University of Pittsburgh

Authors

  • Erin Sheridan

    • Physics & Astronomy, University of Pittsburgh

  • Lu Chen

    • National Institute of Standard and Technology
    • National Institute of Standards and Technology

  • Qing Guo

    • Physics & Astronomy, University of Pittsburgh
    • Univ of Pittsburgh

  • Jianan Li

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

  • Jung-Woo Lee

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

  • Chang-Beom Eom

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

  • Patrick Irvin

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

  • Jeremy Levy

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