Inducing metallicity in graphene nanoribbons via zero-mode superlattices
Inducing metallicity in graphene nanoribbons via zero-mode superlattices
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DOI：
10.1126/science.aay3588
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发表时间：
2020-09-25
期刊：
影响因子：
56.9
通讯作者：
Crommie, Michael F.
中科院分区：
文献类型：
--
作者：
Rizzo, Daniel J.;Veber, Gregory;Crommie, Michael F.
在石墨烯纳米带（GNR）中设计和制造稳健的金属态是具有挑战性的，因为当石墨烯以纳米长度尺度图案化时，横向量子限制和多电子相互作用诱导电子带隙。自下而上合成的最新发展使得设计和表征原子精确的GNR成为可能，但实现GNR金属性的策略一直难以捉摸。在这里，我们展示了一个一般的技术，诱导金属性GNRs插入一个对称的超晶格的零能量模式，否则半导体GNRs。我们使用扫描隧道光谱以及第一性原理密度泛函理论和紧束缚计算来验证所得到的金属性。我们的研究结果表明，金属带宽GNRs可以在很宽的范围内进行调谐，通过控制重叠的零模波函数通过故意的亚晶格对称性破缺。
The design and fabrication of robust metallic states in graphene nanoribbons (GNRs) are challenging because lateral quantum confinement and many-electron interactions induce electronic band gaps when graphene is patterned at nanometer length scales. Recent developments in bottom-up synthesis have enabled the design and characterization of atomically precise GNRs, but strategies for realizing GNR metallicity have been elusive. Here we demonstrate a general technique for inducing metallicity in GNRs by inserting a symmetric superlattice of zero-energy modes into otherwise semiconducting GNRs. We verify the resulting metallicity using scanning tunneling spectroscopy as well as first-principles density-functional theory and tight-binding calculations. Our results reveal that the metallic bandwidth in GNRs can be tuned over a wide range by controlling the overlap of zero-mode wave functions through intentional sublattice symmetry breaking.