在二维电子气中制造的非周期性石墨烯结构的操控和特性研究。

Manipulation and characterization of aperiodical graphene structures created in a two-dimensional electron gas.

机构信息

Department of Physics, The Hong Kong University of Science and Technology, Hong Kong, China.

Department of Physics, University of California, Berkeley, California 94720-7300, USA and Material Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA.

出版信息

Phys Rev Lett. 2014 Nov 7;113(19):196803. doi: 10.1103/PhysRevLett.113.196803.

DOI:10.1103/PhysRevLett.113.196803

PMID:25415917

Abstract

We demonstrate that Dirac fermions can be created and manipulated in a two-dimensional electron gas (2DEG). Using a cryogenic scanning tunneling microscope, we arranged coronene molecules one by one on a Cu(111) surface to construct artificial graphene nanoribbons with perfect zigzag (ZGNRs) or arm-chairedges and confirmed that new states localized along the edges emerge only in the ZGNRs. We further made and studied several typical defects, such as single vacancies, Stone-Wales defects, and dislocation lines, and found that all these defects introduce localized states at or near the Dirac point in the quasiparticle spectra. Our results confirm that artificial systems built on a 2DEG provide rigorous experimental verifications for several long-sought theoretical predications of aperiodic graphene structures.

摘要

我们证明了在二维电子气（2DEG）中可以产生和操纵狄拉克费米子。我们使用低温扫描隧道显微镜，将蒄（coronene）分子逐个排列在 Cu(111)表面上，构建了具有完美锯齿（ZGNRs）或扶手椅边缘的人工石墨烯纳米带，并证实只有在 ZGNRs 中才会出现沿边缘局域的新状态。我们进一步制造并研究了几种典型的缺陷，如单个空位、Stone-Wales 缺陷和位错线，发现所有这些缺陷都会在准粒子能谱中在或接近狄拉克点处引入局域态。我们的结果证实，在 2DEG 上构建的人工系统为非周期性石墨烯结构的几个长期寻求的理论预测提供了严格的实验验证。