摘要
二维量子材料由于其展现出的许多新奇特质而受到了普遍关注。当二维量子材料组成同质结或异质结时,晶格常数和层间旋转角度会使体系产生新的超晶格结构,从而导致一系列电子能带结构和物理性质的变化。文章首先围绕着超晶格结构所带来的晶格空间结构以及能带结构的变化展开讨论,主要介绍了由此产生的超晶格狄拉克点、莫尔激子和原子重构等新奇物性。除此之外,超晶格结构会使电子的费米速度在一组特定的旋转角度下消失,产生平带。这会导致该区域的物理性质由电子之间的相互作用能主导,从而产生显著地改变。这些由电子之间强关联现象所引起的新奇物性,成为了近些年凝聚态物理等研究领域的前沿课题之一。在这里,文章主要围绕着关联绝缘态、超导、电子晶体和轨道磁性等介绍了与电子之间强关联现象有关的内容,并在最后对超晶格结构未来的发展方向进行了展望。
Two-dimensional quantum materials have attracted widespread attention due to their manifestation of numerous novel and unique characteristics.When two-dimensional quantum materials are stacked to form homojunctions or heterojunctions,variations in lattice constants and interlayer rotation angles give rise to new superlattice structures,consequently leading to a series of changes in the electronic band structures and physical properties.In this article,the discussion begins by focusing on the alterations in the lattice spatial structure and band structure resulting from the presence of the superlattice structure,such as superlattice Dirac points,Moiré excitons,and atomic reconstructions.Moreover,at specific rotation angles,the Fermi velocity of electrons will diminish at discrete angles due to the influence of the superlattice structure,giving rise to the creation of flat bands.This will cause a significant change in the physical properties of this region as they are predominantly governed by the interaction energy between electrons.These novel physical properties,arising from strong electron-electron correlations,have become one of the forefront topics in the field of condensed matter physics.Here,the article primarily focuses on subjects pertaining to strong electron-electron correlations,such as correlated insulators,superconductivity,electron crystals,and orbital magnetism.And it offers a forward-looking perspective on the future development directions of superlattice structures.
作者
薛禹承
王英博
姜宇航
XUE Yucheng;WANG Yingbo;JIANG Yuhang(Department of Physical Sciences,University of Chinese Academy of Sciences,Beijing 100049,China;College of Materials Sciences and Opto-Electronic Technology,University of Chinese Academy of Sciences,Beijing 100049,China)
出处
《真空科学与技术学报》
CAS
CSCD
北大核心
2024年第4期279-305,共27页
Chinese Journal of Vacuum Science and Technology
基金
国家自然科学基金项目(12074377)
中央高校基本科研业务费专项资金,中国科学院国际伙伴计划(211211KYSB20210007)。
关键词
二维量子材料
莫尔超晶格
平带
强关联效应
Two-dimensional quantum material
Moirésuperlattice
Flat band
Strong correlation effect
