Nano-light Manipulation of Moiré Photodynamics in a Scanning Tunneling Microscope

Oral-In-person

Abstract

Harnessing photo-carriers within Moiré potentials provides a powerful route to manipulate quantum phases in two-dimensional (2D) materials, yet optical access at the nanoscale is fundamentally limited by diffraction. We present a fiber-based optical-scanning tunneling microscope (optical-STM) that achieves sub-diffraction, plasmon-enhanced nano-illumination, enabling concurrent local photoexcitation and electronic spectroscopy with sub-nanometer precision. Applied to WSe2/WS2 Moiré superlattices, this technique uncovers a complex landscape of light-induced electronic phenomena, including spatially dependent band realignment, photo-carrier dynamics modulated by local disorder, and photoexcited site-selective modulation within individual Moiré unit cells. Our results demonstrate a versatile platform for programmable, nanoscale light–matter interaction engineering in quantum materials.

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Presenters

  • Xuehao Wu

    • Columbia University

Authors

  • Xuehao Wu

    • Columbia University

  • Ziyu Liu

    • Columbia University

  • Yiping Wang

    • Columbia University

  • Aya Tazi

  • Yiliu Li

    • Columbia University

  • Thomas Darlington

    • Columbia University

  • Sanat Ghosh

  • Madisen Holbrook

    • Columbia University

  • Luke Holtzman

    • Columbia University

  • Katayun Barmak

    • Columbia University

  • James Hone

    • Columbia University

  • Cory Dean

    • Columbia University

  • Dmitri Basov

  • James Schuck

  • Xiaoyang Zhu

    • Columbia University

  • Abhay Pasupathy

    • Columbia University