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

IF 47.3 1区综合性期刊 Q1 MULTIDISCIPLINARY SCIENCES

Science Pub Date : 2026-10-22 DOI:10.1126/science.aee6967

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

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引用次数: 0

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.

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广义Wigner晶体量子熔化中的成像电子-空穴不对称性

二维moirir材料提供了一个多功能的平台来探索强相关系统的相变。利用扫描隧道显微镜，研究人员在电子掺杂的近60°扭曲的二硒化钼双分子层中，对广义Wigner晶体（GWCs）和Mott绝缘体（MIs）的密度驱动熔化进行了成像，这些双分子层具有三角形摩尔超晶格。我们观察到GWC熔化过程中明显的电子-空穴不对称性：空穴掺杂的GWCs产生相互作用驱动的无序态，而电子掺杂的GWCs熔化成离域的类液体态。这种不对称性是由于莫尔维尔超晶格的粒子-空穴对称性被打破，在GWC凝结过程中产生了具有不同动量几何形状的电子和空穴费米口袋。MI态熔化时没有这种不对称性，这与不存在破坏对称性的密度调制是一致的。这项工作提供了当GWCs经历量子熔化转变时出现的涌现阶段的直接可视化。

本文章由计算机程序翻译，如有差异，请以英文原文为准。

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来源期刊

Science 综合性期刊-综合性期刊

CiteScore

61.10

自引率

0.90%

发文量

审稿时长

2.1 months

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