April 7 - 11, 2025
Seattle, Washington
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2025 MRS Spring Meeting & Exhibit
QT05.05.01

Visualizing the Impact of Quenched Disorders on Electron Wigner Crystals

When and Where

Apr 9, 2025
2:00pm - 2:30pm
Summit, Level 4, Room 443

Presenter(s)

Co-Author(s)

Zhehao Ge1,Zehao He1,Qize Li1,Ziyu Xiang1,Jianghan Xiao1,Wenjie Zhou1,Mit Naik1,Salman Kahn1,Renee Sailus2,Rounak Banerjee2,Takashi Taniguchi3,Kenji Watanabe3,Sefaattin Tongay2,Steven Louie1,Feng Wang1,Michael Crommie1

University of California, Berkeley1,Arizona State University2,National Institute for Materials Science3

Abstract

Zhehao Ge1,Zehao He1,Qize Li1,Ziyu Xiang1,Jianghan Xiao1,Wenjie Zhou1,Mit Naik1,Salman Kahn1,Renee Sailus2,Rounak Banerjee2,Takashi Taniguchi3,Kenji Watanabe3,Sefaattin Tongay2,Steven Louie1,Feng Wang1,Michael Crommie1

University of California, Berkeley1,Arizona State University2,National Institute for Materials Science3
Understanding electronic systems with both strong electron-electron interactions and electron-disorder interactions is challenging. In a pure low-density two-dimensional (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 ~38. However, in real materials, defects and impurities that act as quenched disorder potentials are always present, which can alter the behavior of low-density 2D electronic systems compared to their disorder-free limit. For example, it is predicted that quenched disorders can distort the triangular lattice of a pure 2D WC and reduce the critial rs for the transition of electrons from a liquid state to a solid state due to their pinning effect. Despite these predictions, microscopic characterization of the effects of quenched disorders on electron WCs remains limited. Here, I will present our recent results on the scanning tunneling microscope (STM) study of disordered electron WCs in gate-tunable bilayer MoSe2 devices. In our experiments, MoSe2 atomic defects that act as different types of disorder potentials, such as repulsive versus attractive and long-range versus short-range, were identified. The impact of these different types of disorder potentials on the wavefunction and quantum melting behavior of disordered electron WCs will be discussed in this talk.

Keywords

2D materials | defects | scanning tunneling microscopy (STM)

Symposium Organizers

Jun Xiao, University of Wisconsin-Madison
Judy Cha, Cornell University
Xiao-Xiao Zhang, University of Florida
Unai Atxitia Macizo, Consejo Superior de Investigaciones Científicas

Symposium Support

Platinum
Gordon and Betty Moore Foundation

Session Chairs

Ying Wang
Jun Xiao

In this Session