An Air-Stable and Atomically Thin Graphene/Gallium Superconducting Heterostructure

Autor: Bersch, Brian, Briggs, Natalie, Wang, Yuanxi, Jiang, Jue, Wang, Ke, Dong, Chengye, Subramanian, Shruti, Fu, Mingming, Zou, Qiang, Chuang, Ya-Wen, Gai, Zheng, Li, An-Ping, Zhu, Jun, Chang, Cui-Zu, Crespi, Vincent H., Robinson, Joshua A.
Rok vydání: 2019
Předmět:
Druh dokumentu: Working Paper
Popis: Two-dimensional layered and atomically thin elemental superconductors may be key ingredients in next-generation quantum technologies, if they can be stabilized and integrated into heterostructured devices under ambient conditions. However, atomically thin elemental superconductors are largely unexplored outside ultra-high vacuum due to rapid oxidation, and even 2D layered superconductors require complex encapsulation strategies to maintain material quality. Here we demonstrate environmentally stable, single-crystal, few-atom-thick superconducting gallium, 2D-Ga, produced by confinement heteroepitaxy (CHet) at the interface of epitaxial graphene (EG) and silicon carbide (SiC). 2D-Ga becomes superconducting at 4 K; this elevation over bulk alpha-Ga (Tc~1 K) is primarily attributed to an increased density of states at the Fermi level as the incipient Ga-Ga dimerization seen in alpha-Ga is suppressed by epitaxy to SiC. We also demonstrate the importance of controlling SiC surface morphology (i.e. step height) and defect-engineering in graphene layers prior to intercalation to achieve large-area uniform 2D-Ga layers with isotropic transport properties. This work demonstrates that unique 2D forms of 3D materials can be stabilized at the EG/SiC interface, which represents a scalable route towards air-stable crystalline 2D superconductors as a potential foundation for next-generation quantum technologies.
Comment: V1: 11 pages of main text with 3 figures, 17 pages of supplemental with 13 figures; V2: Reference added (Ref16), reference updated (Ref15), reference removed (formally Ref30 in V1)
Databáze: arXiv
Externí odkaz: