近日，西班牙马德里纳米科学高级研究所Francisco Guinea团队研究了扭曲各向异性同质双层中的莫尔坍缩和Luttinger液体。相关论文于2026年3月11日发表在《美国科学院院刊》杂志上。
研究组提出将扭曲各向异性同质双层作为一类独特的莫尔系统，其特征是存在独特的“魔角”θM，其中莫尔晶胞在该角度下发生塌缩。不同于传统莫尔材料研究主要关注小角度晶格失配，研究组证明这种莫尔塌缩现象普遍存在于大扭曲角下的扭曲各向异性同质双层中。塌缩角θM很可能导致准晶行为以及强关联态的形成，这些强关联态并非源于平带，而是来源于超各向异性电子态——非费米液相可在此类电子态中稳定存在。
该研究基于对扭曲双层黑磷的广泛第一性原理计算，建立了连续介质电子模型，从而能详细探究这一原型系统中涌现的莫尔塌缩特征。研究表明，当扭曲角趋近θM时，（滑动）液体涌现的温度稳定性判据通常能够得到满足。此外，研究组明确构建了塌缩态单粒子一维连续介质哈密顿量，并给出了适用于低掺杂水平的全相互作用哈密顿量。分析揭示出多通道液体丰富多变的相图，其可能因大扭曲角下的谷自由度而得到增强。
附：英文原文
Title: Moiré collapse and Luttinger liquids in twisted anisotropic homobilayers
Author: de Sousa, Duarte J. P., Lee, Seungjun, Guinea, Francisco, Low, Tony
Issue&Volume: 2026-3-11
Abstract: We introduce twisted anisotropic homobilayers as a distinct class of moiré systems, characterized by a distinctive “magic angle,” θM, where the moiré unit cell collapses. Unlike conventional studies of moiré materials, which primarily focus on small lattice misalignments, we demonstrate that this moiré collapse occurs at large twist angles in generic twisted anisotropic homobilayers. The collapse angle, θM, is likely to give rise quasi-crystal behavior as well as to the formation of strongly correlated states, that arise not from flat bands, but from the presence of ultra-anisotropic electronic states, where non-Fermi liquid phases can be stabilized. In this work, we develop a continuum model for electrons based on extensive ab initio calculations for twisted bilayer black phosphorus, enabling a detailed study of the emerging moiré collapse features in this prototypical system. We show that the (temperature) stability criterion for the emergence of (sliding) Luttinger liquids is generally met as the twist angle approaches θM. Furthermore, we explicitly formulate the collapsed single-particle one-dimensional (1D) continuum Hamiltonian and provide the fully interacting, Hamiltonian applicable at low doping levels. Our analysis reveals a rich landscape of multichannel Luttinger liquids, potentially enhanced by valley degrees of freedom at large twist angles.
DOI: 10.1073/pnas.2527371123
Source: https://www.pnas.org/doi/abs/10.1073/pnas.2527371123