Electrostatic single exciton trapping in a 2D semiconductor heterostructure using nanopatterned graphene

ORAL

Abstract

Interlayer excitons (IXs) in 2D semiconductors have long lifetimes and spin-valley coupled physics, with a long-standing goal of single exciton trapping for quantum applications. In this work, we use a nano-patterned graphene gate to create an electrostatic IX trap. In photoluminescence measurements, we observe narrow linewidth emission, which is a signature of strong spatial confinement, and a unique power-dependent blue-shift of IX energy, with jumps between discrete emission energies. We attribute these jumps to quantized increases of the number occupancy of IXs within the trap. We compare these results to a theoretical model to assign the lowest energy emission line to single IX recombination, indicating that we can create a population of a single exciton within our trap using low laser excitation power. These traps are advantageous over other trapping methods involving strain or moiré potentials due to their deterministic lithographically defined process, 100 meV energy tunability by applied gate voltage, and scalability to create large arrays of single quantum emitters with controllable placement.

*JRS and BJL acknowledge support from the National Science Foundation Grant. Nos. ECCS-2054572 and DMR-2003583 and the Army Research Office under Grant no. W911NF-20-1-0215. JRS acknowledges support from Air Force Office Scientific Research Grant Nos. FA9550-18-1-0390 and FA9550-21-1-0219. BJL acknowledges support from the Army Research Office under Grant no. W911NF-18-1-0420. DGM acknowledges support from the Gordon and Betty Moore Foundation’s EPiQS Initiative, Grant GBMF9069. K.W. and T.T. acknowledge support from JSPS KAKENHI (Grant Numbers 19H05790, 20H00354 and 21H05233). Plasma etching was performed using a Plasmatherm reactive ion etcher acquired through an NSF MRI grant, award no. ECCS-1725571.

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Publication: Single exciton trapping in an electrostatically defined 2D semiconductor quantum dot. arXiv:2206.13427. Accepted for publication in Physical Review B.

Presenters

  • Daniel N Shanks

    • University of Arizona

Authors

  • Daniel N Shanks

    • University of Arizona

  • Fateme Mahdikhanysarvejahany

    • University of Arizona

  • David G Mandrus

    • University of Tennessee
    • Oak Ridge National Laboratory

  • Michael Koehler

    • University of Tennessee
    • University of Tennessee, Knoxville

  • Takashi Taniguchi

    • National Institute for Materials Science
    • Kyoto Univ
    • International Center for Materials Nanoarchitectonics, National Institute of Materials Science
    • Kyoto University
    • International Center for Materials Nanoarchitectonics, National Institute for Materials Science, 1-1 Namiki, Tsukuba 305-044, Japan
    • International Center for Materials Nanoarchitectonics, National Institute for Materials Science
    • National Institute for Materials Science, Japan
    • National Institute For Materials Science
    • NIMS
    • National Institute for Material Science
    • International Center for Materials Nanoarchitectonics, National Institute for Materials Science, Tsukuba, Japan
    • NIMS Japan

  • Kenji Watanabe

    • National Institute for Materials Science
    • Research Center for Functional Materials, National Institute of Materials Science
    • Research Center for Functional Materials, National Institute for Materials Science, 1-1 Namiki, Tsukuba 305-044, Japan
    • NIMS
    • Research Center for Functional Materials, National Institute for Materials Science
    • National Institute for Materials Science, Japan
    • Research Center for Functional Materials, National Institute for Materials Science, Tsukuba, Japan
    • NIMS Japan

  • Brian J LeRoy

    • University of Arizona

  • John Schaibley

    • University of Arizona