近日，美国华盛顿大学Xu, Xiaodong团队研究了扭曲MoTe₂中通过任意子-三重子的分数电荷特征。2026年2月4日出版的《自然》杂志发表了这项成果。

电子电荷e的分数量子化是强电子相互作用产生的最显著现象之一。一个著名范例是分数量子霍尔效应态中出现带有分数电荷的任意子。近年来，无需朗道能级的晶格类比系统——零磁场分数量子反常霍尔绝缘体已实现。该体系为研究任意子提供了独特平台，但其探测仍面临挑战。

研究组报道了在扭曲双层二碲化钼中观察到的新型激子复合体：任意子-三重子——由三重子与分数电荷结合形成。量子受限激子的光致发光光谱揭示了仅出现在轻微掺杂分数量子反常霍尔绝缘体态中的新峰。这些光谱特征相对于未掺杂态中的三重子发生红移，但具有相同的电场、温度和磁场依赖特性。该现象表明其来源于三重子与基本准粒子（即任意子）的结合。关键证据在于，−2/3和−3/5分数量子反常霍尔绝缘体态中任意子-三重子的结合能之比与预期分数电荷比值e/3比e/5相符，这为分数电荷的存在提供了强有力证据。

该研究结果回应了分数量子反常霍尔绝缘体物理中的一个基本问题，并确立了利用三重子光谱学探测分数电荷激发的有效方法，为基于输运和隧穿的探测手段提供了重要补充。

附：英文原文

Title: Signatures of fractional charges via anyon–trions in twisted MoTe2

Author: Li, Weijie, Wang Beach, Christiano, Hu, Chaowei, Taniguchi, Takashi, Watanabe, Kenji, Chu, Jiun-Haw, Imamolu, Ata, Cao, Ting, Xiao, Di, Xu, Xiaodong

Issue&Volume: 2026-02-04

Abstract: Fractionalization of the electron charge e is one of the most striking phenomena arising from strong electron–electron interactions. A celebrated example is the emergence of anyons with fractional charges in fractional quantum Hall effect (FQHE) states1,2,3,4,5,6,7,8,9,10,11,12,13. Recently, zero-field fractional Chern insulators (FCIs)14,15,16,17,18,19, lattice analogues of the FQHE states that form without Landau levels, have been realized20,21. FCIs provide a unique platform to investigate anyons, yet their detection remains a challenge. Here we report the observation of anyon–trions, a new type of excitonic complex formed by binding a trion with a fractional charge in twisted MoTe2 bilayers. Photoluminescence spectroscopy of quantum-confined excitons reveals emergent peaks that appear only within slightly doped FCI states. The new spectral features are red-shifted relative to the trions in undoped FCIs, but share the same electric field, temperature and magnetic field dependence. These observations suggest their origin as trions binding with elementary quasi-particles, that is, anyon–trions. Crucially, the ratio of binding energies between the anyon–trions in the 2/3 and 3/5 FCI states matches the expected fractional charge ratio of e/3 to e/5. This provides strong evidence for fractional charges in FCI—an essential property of anyons. Our results address a fundamental question in FCI physics and establish trion spectroscopy as a powerful probe of fractionally charged excitations, complementary to transport- and tunnelling-based approaches.

DOI: 10.1038/s41586-026-10101-w

Source: https://www.nature.com/articles/s41586-026-10101-w