Tencent Meeting：904-244-442，会议密码：260609

Inviter: 汪非凡 副研究员

Contact: 万源 研究员

汪非凡 副研究员

田春璐 cltian@iphy.ac.cn

主办方：中国科学院物理研究所、松山湖材料实验室

About the speaker

Jue Wang is an assistant professor in the Department of Physics at the Hong Kong University of Science and Technology. He is an experimental condensed matter physicist with broad interests in low-dimensional and strongly correlated quantum phenomena. His research seeks to create novel quantum matters, advance our understanding of them, and explore their potential in the ongoing quantum revolution. To this end, his group develops and employs a wide range of optical spectroscopies and techniques, especially those using ultrafast lasers, in combination with nanofabrication of electronic devices, precision electrical measurements, and low-temperature techniques capable of cooling electrons down to the 10 mK regime.

Jue Wang received his B.S. from Peking University in 2014 and his Ph.D. from Columbia University in 2020. He subsequently held postdoctoral positions at Columbia University from 2020 to 2021 and at Harvard University from 2021 to 2025, before joining HKUST. He is a recipient of the 2026 Croucher Tak Wah Mak Innovation Award, Harvard Quantum Initiative Postdoctoral Fellowship, and the Columbia University Traube Fellowship.

Abstract

In this talk, I will discuss the quantum melting of a two-dimensional (2D) electron Wigner crystal in monolayer MoSe₂. In an ideal 2D electron system, increasing carrier density drives a transition from a Wigner crystal to an electron liquid. The long-range nature of Coulomb interactions is predicted to preclude a direct first-order transition, instead giving rise to intermediate microemulsion phases in which crystalline and liquid domains microscopically coexist. Recent studies have shown that monolayer MoSe₂ can host Wigner crystals without the need for an external magnetic field or periodic potential. Using exciton sensing techniques based on magneto-reflectance spectroscopy, we were able to probe the charge order and magnetic properties of the Wigner crystal, calibrate its electron temperature, and find compelling evidence for the emergence of a microemulsion phase. Furthermore, we found a non-Fermi liquid phase with enhanced spin susceptibility. We mapped the temperature-density phase diagram for the 2D electron system at ultralow temperatures and observed the Pomeranchuk effect arising from the large spin entropy of Wigner crystals. Related aspects of this quantum melting phenomenology are also supported by recent scanning tunneling microscopy studies.