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Scanning tunneling spectroscopy on single crystal MgB2

被引：38
作者：
Eskildsen, MR
Kugler, M
Levy, G
Tanaka, S
Jun, J
Kazakov, SM
Karpinski, J
Fischer, O
机构：
[1] Univ Geneva, Dept Phys Mat Condensee, CH-1211 Geneva 4, Switzerland
[2] Kansai Adv Res Ctr, Commun Res Lab, Nishi Ku, Iwaoka, Japan
[3] Swiss Fed Inst Technol, Solid State Phys Lab, CH-8093 Zurich, Switzerland
来源：
PHYSICA C-SUPERCONDUCTIVITY AND ITS APPLICATIONS | 2003年 / 385卷 / 1-2期
关键词：
scanning tunneling spectroscopy; vortex imaging; multi-gap spectroscopy;
D O I：
10.1016/S0921-4534(02)02301-8
中图分类号：
O59 [应用物理学];
学科分类号：
摘要：
We report on the results of scanning tunneling spectroscopy measurements on single crystals of MgB2. Tunneling was performed both parallel and perpendicular to the crystalline c-axis. In the first case, a single superconducting gap (Delta(pi) = 2.2 meV) associated with the pi-band is observed. Tunneling parallel to the ab-plane reveals an additional, larger gap (Delta(sigma) similar to 7 meV) originating in the highly 2D sigma-band. Vortex imaging in the pi-band was performed with the field and tunnel current parallel to the c-axis. The vortices have a large core size compared to estimates based on H-c2, and show an absence of localized states in the core. Furthermore, superconductivity between the vortices is rapidly suppressed by an applied field. A comparison to specific heat measurements is performed. (C) 2002 Elsevier Science B.V. All rights reserved.
引用
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页码：169 / 176
页数：8
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