2015/07/31 by A. W. Tsen, Adam W. Tsen, B. Hunt +16
Physics and Astronomy · #Condensed matter physics #Electron #Ground state #Magnetic field #Materials science #Metal #Phase (matter) #Phase transition #Physics #Physics of Superconductivity and Magnetism #Quantum #Quantum and electron transport phenomena #Quantum mechanics #Quantum phase transition #Superconductivity #Topological Materials and Phenomena #cond-mat.supr-con
paper · pdf · doi:10.1038/nphys3579
9 pages: 6 pages main text, 3 pages supplementary figures
arxiv created 2015/10/05 · openalex publication_date 2015/12/07 · arxiv updated 2016/03/23 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/06
Two-dimensional (2D) materials are not expected to be metals at low temperature due to electron localization. Consistent with this, pioneering studies on thin films reported only superconducting and insulating ground states, with a direct transition between the two as a function of disorder or magnetic field. However, more recent works have revealed the presence of an intermediate metallic state occupying a substantial region of the phase diagram whose nature is intensely debated. Here, we observe such a state in the disorder-free limit of a crystalline 2D superconductor, produced by mechanical co-lamination of NbSe2 in inert atmosphere. Under a small perpendicular magnetic field, we induce a transition from superconductor to the intermediate metallic state. We find a new power law scaling with field in this phase, which is consistent with the Bose metal model where metallic behavior arises from strong phase fluctuations caused by the magnetic field.