近日，美国加州大学伯克利分校Feng Wang团队研究了在无序二维维格纳固体中成像量子熔化。该研究于2025年5月15日发表在《科学》杂志上。

二维强相互作用的电子在低密度下结晶成固体相，称为维格纳晶体，在高密度下形成费米液体。在中等密度下，二维固体在临界密度附近演变成强相关液相。

研究组使用无创扫描隧道显微镜成像技术观察了无序维格纳固体在双层二硒化钼（MoSe₂）中的量子熔化。在低密度下，维格纳固体形成由局部无序固定的纳米晶畴。随着固相密度的增加，其表现出量子致密化行为。在阈值密度以上，维格纳固体局部熔化，进入固体和液体共存的混合相。液体区域在更高的密度下扩大并形成一个渗流网络。

附：英文原文

Title: Imaging quantum melting in a disordered 2D Wigner solid

Author: Ziyu Xiang, Hongyuan Li, Jianghan Xiao, Mit H. Naik, Zhehao Ge, Zehao He, Sudi Chen, Jiahui Nie, Shiyu Li, Yifan Jiang, Renee Sailus, Rounak Banerjee, Takashi Taniguchi, Kenji Watanabe, Sefaattin Tongay, Steven G. Louie, Michael F. Crommie, Feng Wang

Issue&Volume: 2025-05-15

Abstract: Two-dimensional strongly interacting electrons crystalize into a solid phase known as the Wigner crystal at low densities and form a Fermi liquid at high densities. At intermediate densities, the two-dimensional solid evolves into a strongly correlated liquid phase around a critical density. We observed this quantum melting of a disordered Wigner solid in bilayer molybdenum diselenide (MoSe2) using a noninvasive scanning tunneling microscopy imaging technique. At low densities, the Wigner solid forms nanocrystalline domains pinned by local disorder. It exhibits a quantum densification behavior with increased densities in the solid phase. Above a threshold density, the Wigner solid melts locally and enters a mixed phase in which solid and liquid regions coexist. The liquid regions expand and form a percolation network at even higher densities.

DOI: ado7136

Source: https://www.science.org/doi/10.1126/science.ado7136