Scanning tunneling microscopy study of the superconducting properties of three-atomic-layer Pb films

Journal Article · Mon Dec 09 00:00:00 EST 2013 · Applied Physics Letters

DOI:https://doi.org/10.1063/1.4848219· OSTI ID:22253781

Wang, Yilin; Li, Zhi; Wang, Lili; He, Ke; Ma, Xucun ^[1]; Chen, Mu ^[1]; Xue, Qi-Kun ^[2]

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1. State Key Laboratory for Surface Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190 (China)
2. State Key Laboratory of Low-Dimensional Quantum Physics, Department of Physics, Tsinghua University, Beijing 100084 (China)

Ultrathin Pb films with a thickness of three monolayers (ML) were prepared on α-√(3)×√(3)Pb/Si(111) (Pb-SIC) substrate by molecular beam epitaxy. Despite significant defect scattering, low temperature scanning tunneling microscopy reveals a high superconducting transition temperature T{sub c} of 6.9 K, compared with the bulk T{sub c} (7.2 K). By applying external magnetic field, magnetic vortices were directly imaged, which demonstrates the robustness of superconductivity. By comparing to nearly free-standing Pb films on graphitized SiC (0001) substrate, we suggest that the higher T{sub c} of 3 ML Pb films on Pb-SIC originates from the combined effects of quantum confinement and substrate-enhanced electron-phonon coupling.

• OSTI ID: 22253781
• Journal Information: Applied Physics Letters, Vol. 103, Issue 24; Other Information: (c) 2013 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA); ISSN 0003-6951
• Country of Publication: United States
• Language: English

Related Subjects

75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
ELECTRON-PHONON COUPLING
FILMS
LAYERS
MAGNETIC FIELDS
MAGNETIC FLUX
MOLECULAR BEAM EPITAXY
SCANNING TUNNELING MICROSCOPY
SILICON CARBIDES
SUBSTRATES
SUPERCONDUCTIVITY
THICKNESS
TRANSITION TEMPERATURE