Visualizing the Impact of Quenched Disorder on Electron Wigner Solids

ORAL

Abstract

Understanding electronic systems that have both strong electron-electron interactions and electron-disorder interactions is challenging. In a disorder-free bare 2D electronic system it is well known that electrons form a Wigner crystal (WC) when the ratio (rs) between electron-electron Coulomb repulsion energy and electron kinetic energy exceeds ~37. In real materials, however, defects and impurities are always present and can alter electronic behavior compared to the disorder-free limit. For example, it has been predicted that quenched disorder can distort the triangular lattice of a pure 2D WC and reduce the critical rs​ at which melting occurs due to pinning effects. Real-space experimental characterization of the effects of quenched disorder on WCs, however, remains limited. Here I will present results from our recent scanning tunneling microscopy (STM) study of disordered electron WCs in gate-tunable bilayer MoSe2 devices. We have observed that different MoSe2​ atomic defects provide disorder potentials that can be characterized as either repulsive or attractive, as well as either long-range or short-range. The impact of these different types of disorder potentials on the wavefunction and quantum melting behavior of disordered electron WCs will be discussed.

–

Presenters

  • Zhehao Ge

    • University of California, Berkeley

Authors

  • Zhehao Ge

    • University of California, Berkeley

  • Zehao He

    • University of California, Berkeley

  • Qize Li

    • University of California, Berkeley

  • Ziyu Xiang

    • University of California, Berkeley

  • Jianghan Xiao

    • University of California, Berkeley

  • Salman A Kahn

    • Lawrence Berkeley National Laboratory

  • Wenjie Zhou

    • University of California, Berkeley

  • Mit H. Naik

    • University of California, Berkeley
    • University of Texas at Austin

  • Renee Sailus

    • Arizona State University

  • Rounak Banerjee

    • Arizona State University

  • Takashi Taniguchi

    • National Institute for Materials Science
    • International Center for Materials Nanoarchitectonics, National Institute for Materials Science
    • Research Center for Materials Nanoarchitectonics, National Institute for Materials Science, 1-1 Namiki, Tsukuba 305-0044, Japan
    • International Center for Materials Nanoarchitectonics, National Institute of Material Science, Tsukuba, Japan
    • Advanced Materials Laboratory, National Institute for Materials Science

  • Kenji Watanabe

    • National Institute for Materials Science
    • NIMS
    • Research Center for Functional Materials, National Institute for Materials Science
    • Research Center for Electronic and Optical Materials, National Institute for Materials Science, 1-1 Namiki, Tsukuba 305-0044, Japan
    • Research Center for Functional Materials, National Institute of Material Science, Tsukuba, Japan
    • National Institute of Materials Science
    • Advanced Materials Laboratory, National Institute for Materials Science

  • Sefaattin Tongay

    • Arizona State University

  • Steven G Louie

    • University of California, Berkeley
    • University of California, Berkeley and Lawrence Berkeley National Lab
    • University of California, Berkeley and Lawrence Berkeley National Laboratory
    • Department of Physics, University of California at Berkeley and Materials Sciences Division, Lawrence Berkeley National Laboratory
    • Department of Physics, University of California at Berkeley, Berkeley, CA, USA and Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA, USA

  • feng wang

    • University of California, Berkeley

  • Michael F Crommie

    • University of California, Berkeley