超晶格中的强相关和超导性
近日，瑞士洛桑联邦理工学院Banerjee, Mitali团队研究了超晶格中的强相关和超导性。2026年1月20日出版的《自然—物理学》杂志发表了这项成果。
超莫尔晶格产生于多个莫尔图案的干涉效应，它通过引入新的微能带并改变能带色散关系，重塑了其所处材料的电子能带结构。同时，莫尔图案诱导产生的平带中存在的强电子相互作用，导致了多种关联态的出现。然而，超莫尔晶格对具有强相互作用的平带体系的影响在很大程度上仍未得到探索。
研究组报道了镜像对称性破缺的转角三层石墨烯中存在的超莫尔晶格，并阐明了其在产生微平带与微狄拉克能带中的作用。研究组展示了超莫尔微平带中相互作用诱导的对称性破缺相，以及超莫尔晶格实现的超导-绝缘体级联转变。该研究证明镜像对称性破缺的转角三层石墨烯中可存在稳健的超导性，并强调了超莫尔晶格作为调控转角多层体系电子性质的额外自由度的重要性。这一发现不仅有助于理解原始莫尔平带中的关联量子相（如超导性），更凸显了利用超莫尔晶格设计与模拟量子相的潜力。
附：英文原文
Title: Strong correlations and superconductivity in the supermoiré lattice
Author: Zhou, Zekang, Shen, Cheng, Kolr^, Krytof, Watanabe, Kenji, Taniguchi, Takashi, Lewandowski, Cyprian, Banerjee, Mitali
Issue&Volume: 2026-01-20
Abstract: The supermoiré lattice, arising from the interference of multiple moiré patterns, reshapes the electronic band structure of the material that hosts it by introducing new mini bands and modifying the band dispersion. Concurrently, strong electronic interactions within the flat bands induced by the moiré pattern lead to the emergence of various correlated states. However, the impact of the supermoiré lattice on the flat band system with strong interactions remains largely unexplored. Here we report the existence of the supermoiré lattice in twisted trilayer graphene with broken mirror symmetry and elucidate its role in generating mini flat bands and mini Dirac bands. We demonstrate interaction-induced symmetry-broken phases in the supermoiré mini flat bands alongside a cascade of superconductor–insulator transitions enabled by the supermoiré lattice. Our work shows that robust superconductivity can exist in twisted trilayer graphene with broken mirror symmetry and underscores the importance of the supermoiré lattice as an additional degree of freedom for tuning the electronic properties in twisted multilayer systems. It also sheds light on the correlated quantum phases such as superconductivity in the original moiré flat bands, and highlights the potential of using the supermoiré lattice to design and simulate quantum phases.
DOI: 10.1038/s41567-025-03131-0
Source: https://www.nature.com/articles/s41567-025-03131-0
