凝聚态物理
范霍夫奇点
物理
哈密顿量(控制论)
鞍点
迪拉克费米子
奇点
电子结构
拓扑(电路)
石墨烯
量子力学
几何学
电子
数学
组合数学
费米能级
数学优化
作者
Young‐Woo Son,Hosub Jin,Sejoong Kim
出处
期刊:Nano Letters
[American Chemical Society]
日期:2022-03-28
卷期号:22 (7): 3112-3117
被引量:10
标识
DOI:10.1021/acs.nanolett.2c00528
摘要
We study the electronic properties of a new planar carbon crystal formed through networking biphenylene molecules. Novel electronic features among carbon materials such as zone-center saddle point and peculiar type-II Dirac fermionic states are shown to exist in the low-energy electronic spectrum. The type-II state here has a nearly flat branch and is close to a transition to type I. Possible magnetic instabilities related to low-energy bands are discussed. Furthermore, with a moderate uniaxial strain, a pair of Dirac points merge with the zone-center saddle point, realizing concurrent Lifshitz transitions of van Hove singularity as well as pair annihilation of the Dirac fermions. A new effective Hamiltonian encompassing all distinctive low-energy states is constructed, revealing a finite winding number of the pseudospin texture around the Dirac point, quantized Zak phases, and topological grain boundary states.
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