Atomically thin half-van der Waals metals enabled by confinement heteroepitaxy
Atomically thin half-van der Waals metals enabled by confinement heteroepitaxy
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DOI：
10.1038/s41563-020-0631-x
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发表时间：
2020-03-10
期刊：
影响因子：
41.2
通讯作者：
Robinson, Joshua A.
中科院分区：
文献类型：
--
作者：
Briggs, Natalie;Bersch, Brian;Robinson, Joshua A.
原子上薄的二维金属可能是下一代量子和光电设备中的关键成分。但是，必须针对环境下降稳定2D金属，并以晶圆量表整合到异质结构设备中。碳化硅和外延石墨烯之间的高能量界面为稳定多种2D金属范围的框架提供了一个有趣的框架。在这里，我们展示了在外延石墨烯和碳化硅的界面上稳定的大区域，环境稳定的单晶2D耐加工，凹和锡。 2D金属在下面的SIC上共价键合，但对石墨烯叠加剂的非键界面呈现。也就是说，它们是“半范德华”金属，其内部梯度在粘结特征中。这些非中心对称2D金属为超导设备，拓扑现象和先进的光电特性提供了令人信服的机会。例如，报告的2D GA是一种超导体，将六个强耦合的GA衍生的电子口袋与一个近几乎近自由电子的Fermi表面结合在一起，紧密接近石墨烯叠加仪的dirac点。Single-Crystal 2D金属在界面处稳定在外延石墨烯和碳化硅之间，具有粘结特征的内部梯度强。限制的2D金属表现出引人注目的超导特性。
Atomically thin two-dimensional (2D) metals may be key ingredients in next-generation quantum and optoelectronic devices. However, 2D metals must be stabilized against environmental degradation and integrated into heterostructure devices at the wafer scale. The high-energy interface between silicon carbide and epitaxial graphene provides an intriguing framework for stabilizing a diverse range of 2D metals. Here we demonstrate large-area, environmentally stable, single-crystal 2D gallium, indium and tin that are stabilized at the interface of epitaxial graphene and silicon carbide. The 2D metals are covalently bonded to SiC below but present a non-bonded interface to the graphene overlayer; that is, they are 'half van der Waals' metals with strong internal gradients in bonding character. These non-centrosymmetric 2D metals offer compelling opportunities for superconducting devices, topological phenomena and advanced optoelectronic properties. For example, the reported 2D Ga is a superconductor that combines six strongly coupled Ga-derived electron pockets with a large nearly free-electron Fermi surface that closely approaches the Dirac points of the graphene overlayer.Single-crystal 2D metals are stabilized at the interface between epitaxial graphene and silicon carbide, with strong internal gradients in bonding character. The confined 2D metals demonstrate compelling superconducting properties.