近日，美国康奈尔大学Jie Shan团队研究了原子双层中的平衡离子液体。该研究于2025年10月16日发表在《科学》杂志上。

三重子是由两个电子与一个空穴，或两个空穴与一个电子构成的束缚态。迄今为止，三重子仅能在掺杂半导体中以光激发态形式被观测到。

研究组报道了在库仑耦合的二硒化钼（MoSe₂）与二硒化钨（WSe₂）单层结构中涌现的平衡态三重子液体。通过将WSe₂中空穴密度电调控至MoSe₂电子密度的两倍，研究组在比费米温度低两个数量级的温度下，成功制备出结合能达毫电子伏量级的平衡态层间三重子。研究组观察到向电子-空穴等离子体的密度调控相变、组成空穴的自旋单态关联性，以及塞曼场诱导的三重子解离现象。该研究为探索固体中复合粒子的关联物态开辟了新路径。

附：英文原文

Title: An equilibrium trion liquid in atomic double layers

Author: Phuong X. Nguyen, Raghav Chaturvedi, Liguo Ma, Patrick Knuppel, Kenji Watanabe, Takashi Taniguchi, Kin Fai Mak, Jie Shan

Issue&Volume: 2025-10-16

Abstract: A trion is a bound state of two electrons and one hole or two holes and one electron. To date, trions have been observed only as optically excited states in doped semiconductors. We report the emergence of an equilibrium trion liquid in Coulomb-coupled molybdenum diselenide (MoSe2) and tungsten diselenide (WSe2) monolayers. By electrically tuning the hole density in WSe2 to be two times the electron density in MoSe2, we generated equilibrium interlayer trions with binding energy in the milli–electron volt energy scale at temperatures two orders of magnitude below the Fermi temperature. We observed a density-tuned phase transition to an electron-hole plasma, spin-singlet correlations for the constituent holes, and Zeeman field–induced dissociation of the trions. Our results pave the way for exploration of the correlated phases of composite particles in solids.

DOI: adn5886

Source: https://www.science.org/doi/10.1126/science.adn5886