Electronic Topological Transition in Sliding Bilayer Graphene
Electronic Topological Transition in Sliding Bilayer Graphene
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DOI：
10.1103/physrevb.84.155410
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发表时间：
2010-12
影响因子：
3.7
通讯作者：
Y. Son;Seon-Myeong Choi;Yoon Pyo Hong;S. Woo;S. Jhi
中科院分区：
文献类型：
--
作者：
Y. Son;Seon-Myeong Choi;Yoon Pyo Hong;S. Woo;S. Jhi
我们从理论上证明，当在任意方向上发生极微小的层间横向位移时，双层石墨烯中的能带和费米面拓扑结构会经历一个非常敏感的转变。这种现象源于滑动运动在狄拉克哈密顿量中产生有效的非阿贝尔矢量势。由于有效非阿贝尔规范场和与无质量电子相关的贝里相之间的独特相互作用，无质量狄拉克费米子的跃迁特征（如对湮灭）由滑动方向决定。跃迁表现为各种可测量的量，如异常态密度、最小电导率和明显的朗道能级谱。
We demonstrate theoretically that the topology of energy bands and Fermi surface in bilayer graphene undergoes a very sensitive transition when extremely tiny lateral interlayer shift occurs in arbitrary directions. The phenomenon originates from a generation of effective non-Abelian vector potential in Dirac Hamiltonian by the sliding motions. The characteristics of the transition such as pair annihilations of massless Dirac fermions are dictated by the sliding direction owing to a unique interplay between the effective non-Abelian gauge fields and Berry's phases associated with massless electrons. The transition manifests itself in various measurable quantities such as anomalous density of states, minimal conductivity, and distinct Landau level spectrum.