Detection of a superconducting phase in a two-atom layer of hexagonal Ga film grown on semiconducting GaN(0001)

Huimin Zhang; Yi Sun; Wei Li; Junping Peng; Can-Li Song; Ying Xing; Qinghua Zhang; Jiaqi Guan; Zhi Li; Yanfei Zhao; Shuaihua Ji; Lili Wang; Ke He; Xi Chen; Lin Gu; Langsheng Ling; Mingliang Tian; Lian Li; X. C. Xie; Jianping Liu; Hui Yang; Qi-Kun Xue; Jian Wang; Xucun Ma

doi:10.1103/physrevlett.114.107003

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arXiv · 1403.5936

Detection of a superconducting phase in a two-atom layer of hexagonal Ga film grown on semiconducting GaN(0001)

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Abstract

The recent observation of superconducting state at atomic scale has motivated the pursuit of exotic condensed phases in two-dimensional (2D) systems. Here we report on a superconducting phase in two-monolayer crystalline Ga films epitaxially grown on wide band-gap semiconductor GaN(0001). This phase exhibits a hexagonal structure and only 0.552 nm in thickness, nevertheless, brings about a superconducting transition temperature Tc as high as 5.4 K, confirmed by in situ scanning tunneling spectroscopy, and ex situ electrical magneto-transport and magnetization measurements. The anisotropy of critical magnetic field and Berezinski-Kosterlitz-Thouless-like transition are observed, typical for the 2D superconductivity. Our results demonstrate a novel platform for exploring atomic-scale 2D superconductor, with great potential for understanding of the interface superconductivity.

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Huimin Zhang, Yi Sun, Wei Li, Junping Peng, Can-Li Song, Ying Xing, Qinghua Zhang, Jiaqi Guan, Zhi Li, Yanfei Zhao, Shuaihua Ji, Lili Wang, Ke He, Xi Chen, Lin Gu, Langsheng Ling, Mingliang Tian, Lian Li, X. C. Xie, Jianping Liu, Hui Yang, Qi-Kun Xue, Jian Wang, Xucun Ma. 2014-03-24. Detection of a superconducting phase in a two-atom layer of hexagonal Ga film grown on semiconducting GaN(0001). https://doi.org/10.1103/physrevlett.114.107003

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