二维材料平带的实现及其新奇量子物态  

Flat bands and related novel quantum states in two-dimensional systems

作　　者：张若寒 任慧莹 何林 Zhang Ruo-Han;Ren Hui-Ying;He Lin(Center for Advanced Quantum Studies,Department of Physics,Beijing Normal University,Beijing 100875,China)

机构地区：[1]北京师范大学物理学系,高等量子研究中心,北京100875

出　　处：《物理学报》2022年第12期220-237,共18页Acta Physica Sinica

基　　金：国家自然科学基金(批准号:12141401,11974050)资助的课题。

摘　　要：在二维材料平带中电子的有效质量急剧增大,电子的库仑排斥能将远远大于电子的动能,电子-电子相互作用效应显著,对应地将会产生一系列新奇的强关联量子物态,如量子霍尔铁磁态、分数量子霍尔效应、量子反常霍尔效应、超导态、Wigner晶体等.因此人们对于二维材料中的平带产生了极大的兴趣.近几年,与平带相关的强关联物性研究成为了凝聚态物理领域的前沿课题.实验上发展了多种方法,例如通过外加强磁场、构筑应变结构、引入转角等方式在二维材料中引入平带.本文通过对二维体系中平带的实现方法及其带来的新奇物理现象进行回顾,希望为相关领域的研究人员提供参考和借鉴.In flat bands of two-dimensional materials, the mass of charge carriers increases dramatically and the Coulomb energy of the charge carriers can be much larger than the quenched kinetic energy. When the flat band is partially filled, electron-electron interactions can drive electrons to form exotic correlated phases, such as quantum Hall ferromagnetism, fractional quantum Hall effect, superconductivity, and quantum anomalous Hall effect. Therefore, flat bands in two-dimensional materials have attracted much attention very recently. In the past few years, the strongly correlated phenomena in flat bands have become a hot topic in community of condensed matter physics. There are several different methods, such as using a perpendicular magnetic field,introducing strained structures, and introducing a twist angle, to realize the flat bands in two-dimensional materials. In this review article, we summarize the methods to realize flat bands in two-dimensional systems and introduce the related novel electronic states when the flat band is partially filled.

关 键 词：平带 HUBBARD模型 强关联效应 新奇量子物态 

分 类 号：O469[理学—凝聚态物理]