论文标题
双层石墨烯中浆果相的间隔量子干扰和测量
Intervalley quantum interference and measurement of Berry phase in bilayer graphene
论文作者
论文摘要
Bernal堆叠双层石墨烯中的手性准粒子具有2π的山谷对比相。这种与沿封闭的费米表面的伪旋转缠绕相关的非数量拓扑结构负责各种新型的电子特性，例如抗Klein隧道，非常规量子霍尔效应和Valley Hall效应1-6。在这里，我们表明，由于原子缺陷/杂质引起的间隔散射引起的量子干扰提供了对双层石墨烯拓扑性质的进一步见解。与手性相反手性的不同山谷之间的散落性手性准粒子经历了伪旋转的旋转，从而导致弗里德尔振荡与波前位错。错位的数量反映了有关伪蛋白纹理的信息，因此可以用来测量浆果阶段7。正如实验和理论上所证明的那样，根据不同sublattices的原子缺陷/杂质，弗里德尔振荡可以表现出n = 4、2或0的其他波前，表征了双层石墨烯的2π浆果相。我们的结果不仅提供了对双层石墨烯中Intervalley量子干扰的全面研究，而且还提供了伪造物理学上的灯光。
Chiral quasiparticles in Bernal-stacked bilayer graphene have valley-contrasting Berry phases of 2π. This nontrival topological structure, associated with the pseudospin winding along a closed Fermi surface, is responsible for various novel electronic properties, such as anti-Klein tunneling, unconventional quantum Hall effect, and valley Hall effect1-6. Here we show that the quantum interference due to intervalley scattering induced by atomic defects/impurities provides further insights into the topological nature of the bilayer graphene. The scattered chiral quasiparticles between distinct valleys with opposite chirality undergoes a rotation of pseudospin that results in the Friedel oscillation with wavefront dislocations. The number of dislocations reflects the information about pseudospin texture and hence can be used to measure the Berry phase7. As demonstrated both experimentally and theoretically, the Friedel oscillation, depending on the atomic defect/impurity at different sublattices, can exhibit N = 4, 2, or 0 additional wavefronts, characterizing the 2π Berry phase of the bilayer graphene. Our results not only provide a comprehensive study of the intervalley quantum interference in bilayer graphene, but also shed lights on the pseudospin physics.
