近日，美国加州大学伯克利分校Michael F. Crommie团队报道了广义维格纳晶体量子熔化中电子-空穴不对称性的成像。相关论文发表在2026年10月22日出版的《科学》杂志上。

二维莫尔材料为探索强关联体系中的相变提供了一个通用平台。研究组利用扫描隧道显微镜，对具有三角形莫尔超晶格的近60°扭转、电子掺杂二硒化钼双层中广义维格纳晶体（GWC）和莫特绝缘体（MI）的密度驱动熔化过程进行了成像。

研究组观察到GWC熔化中显著的电子-空穴不对称性：空穴掺杂的GWC产生相互作用驱动的无序态，而电子掺杂的GWC则熔化为离域的液态样状态。这种不对称性源于莫尔超晶格破缺的粒子-空穴对称性，该对称性在GWC凝聚时产生了具有不同动量几何的电子和空穴费米口袋。MI态的熔化不存在这种不对称性，这与缺乏破缺对称性的密度调制相一致。该工作直接可视化了GWC经历量子熔化转变时出现的新兴相。

附：英文原文

Title: Imaging electron-hole asymmetry in the quantum melting of generalized Wigner crystals

Author: Emma Berger, Michael Arumainayagam, Zhihuan Dong, Lucas Schneider, Tianle Wang, Greyson Nichols, Salman Kahn, Rwik Dutta, Gaoqiang Wang, Takashi Taniguchi, Kenji Watanabe, Mit H. Naik, Michael P. Zaletel, Feng Wang, Michael F. Crommie

Issue&Volume: 2026-10-22

Abstract: Two-dimensional moiré materials provide a versatile platform to explore phase transitions in strongly correlated systems. Using scanning tunneling microscopy, we imaged the density-driven melting of generalized Wigner crystals (GWCs) and Mott insulators (MIs) in electron-doped, near-60°–twisted molybdenum diselenide bilayers featuring a triangular moiré superlattice. We observed notable electron-hole asymmetry in GWC melting: Hole-doped GWCs yielded interaction-driven disordered states, whereas electron-doped GWCs melted into delocalized liquid-like states. This asymmetry arose from the broken particle-hole symmetry of the moiré superlattice, which produced electron and hole Fermi pockets with different momentum geometries upon GWC condensation. MI states melted without such asymmetry, consistent with the absence of a symmetry-breaking density modulation. This work provides direct visualization of the emergent phases that appear as GWCs undergo quantum melting transitions.

DOI: 10.1126/science.aee6967

Source:https://www.science.org/doi/10.1126/science.aee6967