title: Detection of a superconducting phase in a two-atom layer of hexagonal Ga film grown on semiconducting GaN(0001).
abstract: The recent observation of the 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 magnetotransport 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 superconductors, with great potential for understanding the interface superconductivity.
authors: Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China.
authors: Hui-Min
authors: HM
authors: Zhang
authors: International Center for Quantum Materials, School of Physics, Peking University, Beijing 100871, China.
authors: Yi
authors: Y
authors: Sun
authors: State Key Laboratory of Low-Dimensional Quantum Physics, Department of Physics, Tsinghua University, Beijing 100084, China.
authors: Wei
authors: W
authors: Li
authors: Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China.
authors: Jun-Ping
authors: JP
authors: Peng
authors: State Key Laboratory of Low-Dimensional Quantum Physics, Department of Physics, Tsinghua University, Beijing 100084, China.
authors: Can-Li
authors: CL
authors: Song
authors: International Center for Quantum Materials, School of Physics, Peking University, Beijing 100871, China.
authors: Ying
authors: Y
authors: Xing
authors: Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China.
authors: Qinghua
authors: Q
authors: Zhang
authors: Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China.
authors: Jiaqi
authors: J
authors: Guan
authors: Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China.
authors: Zhi
authors: Z
authors: Li
authors: International Center for Quantum Materials, School of Physics, Peking University, Beijing 100871, China.
authors: Yanfei
authors: Y
authors: Zhao
authors: State Key Laboratory of Low-Dimensional Quantum Physics, Department of Physics, Tsinghua University, Beijing 100084, China.|Collaborative Innovation Center of Quantum Matter, 100084 Beijing, China.
authors: Shuaihua
authors: S
authors: Ji
authors: State Key Laboratory of Low-Dimensional Quantum Physics, Department of Physics, Tsinghua University, Beijing 100084, China.|Collaborative Innovation Center of Quantum Matter, 100084 Beijing, China.
authors: Lili
authors: L
authors: Wang
authors: State Key Laboratory of Low-Dimensional Quantum Physics, Department of Physics, Tsinghua University, Beijing 100084, China.|Collaborative Innovation Center of Quantum Matter, 100084 Beijing, China.
authors: Ke
authors: K
authors: He
authors: State Key Laboratory of Low-Dimensional Quantum Physics, Department of Physics, Tsinghua University, Beijing 100084, China.|Collaborative Innovation Center of Quantum Matter, 100084 Beijing, China.
authors: Xi
authors: X
authors: Chen
authors: Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China.|Collaborative Innovation Center of Quantum Matter, 100084 Beijing, China.
authors: Lin
authors: L
authors: Gu
authors: High Magnetic Field Laboratory, Chinese Academy of Sciences, Hefei 230031, Anhui, China.
authors: Langsheng
authors: L
authors: Ling
authors: High Magnetic Field Laboratory, Chinese Academy of Sciences, Hefei 230031, Anhui, China.
authors: Mingliang
authors: M
authors: Tian
authors: Department of Physics, University of Wisconsin, Milwaukee, Wisconsin 53211, USA.
authors: Lian
authors: L
authors: Li
authors: International Center for Quantum Materials, School of Physics, Peking University, Beijing 100871, China.|Collaborative Innovation Center of Quantum Matter, 100084 Beijing, China.
authors: X C
authors: XC
authors: Xie
authors: Suzhou Institute of Nano-Tech and Nano-Bionics, Chinese Academy of Sciences, Jiangsu 215123, China.
authors: Jianping
authors: J
authors: Liu
authors: Suzhou Institute of Nano-Tech and Nano-Bionics, Chinese Academy of Sciences, Jiangsu 215123, China.
authors: Hui
authors: H
authors: Yang
authors: State Key Laboratory of Low-Dimensional Quantum Physics, Department of Physics, Tsinghua University, Beijing 100084, China.|Collaborative Innovation Center of Quantum Matter, 100084 Beijing, China.
authors: Qi-Kun
authors: QK
authors: Xue
authors: International Center for Quantum Materials, School of Physics, Peking University, Beijing 100871, China.|Collaborative Innovation Center of Quantum Matter, 100084 Beijing, China.
authors: Jian
authors: J
authors: Wang
authors: Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China.|State Key Laboratory of Low-Dimensional Quantum Physics, Department of Physics, Tsinghua University, Beijing 100084, China.|Collaborative Innovation Center of Quantum Matter, 100084 Beijing, China.
authors: Xucun
authors: X
authors: Ma