Scanning tunneling spectroscopy on the novel superconductor CaC6

被引:63
作者
Bergeal, N.
Dubost, V.
Noat, Y.
Sacks, W.
Roditchev, D.
Emery, N.
Herold, C.
Mareche, J. -F.
Lagrange, P.
Loupias, G.
机构
[1] Univ Nancy 1, Lab Chim Solide Mineral, CNRS, UMR 7555, F-54506 Vandoeuvre Les Nancy, France
[2] Univ Paris 06, IMPMC, Inst Mineral & Phys Milieux Condenses, UMR 7590, F-75252 Paris 05, France
关键词
D O I
10.1103/PhysRevLett.97.077003
中图分类号
O4 [物理学];
学科分类号
0702 ;
摘要
We present scanning tunneling microscopy and spectroscopy of the newly discovered superconductor CaC6. The tunneling conductance spectra, measured between 3 and 15 K, show a clear superconducting gap in the quasiparticle density of states. The gap function extracted from the spectra is in good agreement with the conventional BCS theory with Delta(0)=1.6 +/- 0.2 meV. The possibility of gap anisotropy and two-gap superconductivity is also discussed. In a magnetic field, direct imaging of the vortices allows us to deduce a coherence length in the ab plane xi(ab)similar or equal to 33 nm.
引用
收藏
页数:4
相关论文
共 19 条
  • [1] MODEL FOR SUPERCONDUCTIVITY IN GRAPHITE-INTERCALATION COMPOUNDS
    ALJISHI, R
    [J]. PHYSICAL REVIEW B, 1983, 28 (01): : 112 - 116
  • [2] Theoretical explanation of superconductivity in C6Ca -: art. no. 237002
    Calandra, M
    Mauri, F
    [J]. PHYSICAL REVIEW LETTERS, 2005, 95 (23)
  • [3] BOUND FERMION STATES ON A VORTEX LINE IN A TYPE-II SUPERCONDUCTOR
    CAROLI, C
    DEGENNES, PG
    MATRICON, J
    [J]. PHYSICS LETTERS, 1964, 9 (04): : 307 - 309
  • [4] The role of the interlayer state in the electronic structure of superconducting graphite intercalated compounds
    Csányi, G
    Littlewood, PB
    Nevidomskyy, AH
    Pickard, CJ
    Simons, BD
    [J]. NATURE PHYSICS, 2005, 1 (01) : 42 - 45
  • [5] DIRECT MEASUREMENT OF QUASIPARTICLE-LIFETIME BROADENING IN A STRONG-COUPLED SUPERCONDUCTOR
    DYNES, RC
    NARAYANAMURTI, V
    GARNO, JP
    [J]. PHYSICAL REVIEW LETTERS, 1978, 41 (21) : 1509 - 1512
  • [6] Superconductivity of bulk CaC6 -: art. no. 087003
    Emery, N
    Hérold, C
    d'Astuto, M
    Garcia, V
    Bellin, C
    Marêché, JF
    Lagrange, P
    Loupias, G
    [J]. PHYSICAL REVIEW LETTERS, 2005, 95 (08)
  • [7] Structural study and crystal chemistry of the first stage calcium graphite intercalation compound
    Emery, N
    Hérold, C
    Lagrange, P
    [J]. JOURNAL OF SOLID STATE CHEMISTRY, 2005, 178 (09) : 2947 - 2952
  • [8] Vortex imaging in the π band of magnesium diboride -: art. no. 187003
    Eskildsen, MR
    Kugler, M
    Tanaka, S
    Jun, J
    Kazakov, SM
    Karpinski, J
    Fischer, O
    [J]. PHYSICAL REVIEW LETTERS, 2002, 89 (18)
  • [9] Two-gap state density in MgB2:: A true bulk property or a proximity effect?: art. no. 177008
    Giubileo, F
    Roditchev, D
    Sacks, W
    Lamy, R
    Thanh, DX
    Klein, J
    Miraglia, S
    Fruchart, D
    Marcus, J
    Monod, P
    [J]. PHYSICAL REVIEW LETTERS, 2001, 87 (17) : 177008 - 1
  • [10] INSERTION OF ALKALINE-EARTH METALS IN GRAPHITE
    GUERARD, D
    CHAABOUNI, M
    LAGRANGE, P
    ELMAKRINI, M
    HEROLD, A
    [J]. CARBON, 1980, 18 (04) : 257 - 264