Andreev reflection spectroscopy evidence for multiple gaps in MgB2 -: art. no. 064513

被引：24
|
作者：
Li, ZZ [1 ]
Tao, HJ [1 ]
Xuan, Y [1 ]
Ren, ZA [1 ]
Che, GC [1 ]
Zhao, BR [1 ]
机构：
[1] Chinese Acad Sci, Ctr Condensed Matter Phys, Beijing 100080, Peoples R China
来源：
PHYSICAL REVIEW B | 2002年 / 66卷 / 06期
关键词：
D O I：
10.1103/PhysRevB.66.064513
中图分类号：
T [工业技术];
学科分类号：
08 ;
摘要：
Andreev reflection tunneling spectroscopy on MgB2/PtIr point contacts have systematically been investigated. By fitting tunneling conductance to Blonder-Tinkham-Klapwijk theory, s-wave superconducting gaps were obtained. The distribution of the obtained gaps unequivocally shows two groups: one centered at 9.8 meV and the other peaked at 2.8 meV with a gap ratio of 3.5. For two typical gaps Delta(1)=1.92 meV and Delta(2)=3.45 meV their temperature-dependent behavior display that Delta(1)(T) unambiguously persists to the bulk T-c, 39 K, and Delta(2)(T) closes at 33 K. The results support multigap scenarios; in addition our experiments yield a much higher value of the large gap than the previous reports and theoretical predictions, indicating there may exist even stronger electron-phonon coupling in MgB2.
引用
收藏
页码：1 / 5
页数：5
相关论文
共 50 条
  • [31] Pressure and isotope effect on the anisotropy of MgB2 -: art. no. 054501
    Schneider, T
    Di Castro, D
    PHYSICAL REVIEW B, 2005, 72 (05)
  • [32] Josephson effect in MgB2 break junctions -: art. no. 097001
    Gonnelli, RS
    Calzolari, A
    Daghero, D
    Ummarino, GA
    Stepanov, VA
    Giunchi, G
    Ceresara, S
    Ripamonti, G
    PHYSICAL REVIEW LETTERS, 2001, 87 (09) : 970011 - 970014
  • [33] Dielectric functions and collective excitations in MgB2 -: art. no. 180507
    Zhukov, VP
    Silkin, VM
    Chulkov, EV
    Echenique, PM
    PHYSICAL REVIEW B, 2001, 64 (18)
  • [34] Multiband model for tunneling in MgB2 junctions -: art. no. 180517
    Brinkman, A
    Golubov, AA
    Rogalla, H
    Dolgov, OV
    Kortus, J
    Kong, Y
    Jepsen, O
    Andersen, OK
    PHYSICAL REVIEW B, 2002, 65 (18) : 1805171 - 1805174
  • [35] Multiband model for penetration depth in MgB2 -: art. no. 054524
    Golubov, AA
    Brinkman, A
    Dolgov, OV
    Kortus, J
    Jepsen, O
    PHYSICAL REVIEW B, 2002, 66 (05) : 545241 - 545245
  • [36] Coherence lengths and anisotropy in MgB2 superconductor -: art. no. 020507
    Dulcic, A
    Pozek, M
    Paar, D
    Choi, EM
    Kim, HJ
    Kang, WN
    Lee, SI
    PHYSICAL REVIEW B, 2003, 67 (02)
  • [37] Current percolation and anisotropy in polycrystalline MgB2 -: art. no. 247002
    Eisterer, M
    Zehetmayer, M
    Weber, HW
    PHYSICAL REVIEW LETTERS, 2003, 90 (24)
  • [38] Reflectance measurements and superconductivity in MgB2 -: Reply -: art. no. 129704
    Marsiglio, F
    PHYSICAL REVIEW LETTERS, 2002, 89 (12)
  • [39] Multiband magnetotransport in the normal state of MgB2 -: art. no. 104519
    Pallecchi, I
    Braccini, V
    d'Agliano, EG
    Monni, M
    Siri, AS
    Manfrinetti, P
    Palenzona, A
    Putti, M
    PHYSICAL REVIEW B, 2005, 71 (10)
  • [40] Anharmonic phonon frequency shift in MgB2 -: art. no. 220509
    Lazzeri, M
    Calandra, M
    Mauri, F
    PHYSICAL REVIEW B, 2003, 68 (22)
12345