Multiple-gap features from break-junction tunneling in the superconducting MgB2

Tomoaki Takasaki, Toshikazu Ekino, Takahiro Muranaka, Takayuki Ichikawa, Hironobu Fujii, Jun Akimitsu

Research output: Contribution to journalArticle

12 Citations (Scopus)

Abstract

Tunneling spectroscopy measurements on polycrystalline MgB2 have been carried out with a break-junction technique. The observed spectra exhibit the multiple-gap feature, which can be expressed by the correlated two-gap model. From the conductance fittings at 4.2 K, the gap parameters can be classified into ΔS = 2:2 ± 0:3 meV, ΔM = 6:0 ± 1:5 meV, and ΔL = ≅ 10 meV. All these gaps exist up to the same critical temperature Tc. The ΔM undergoes various ways of temperature dependence, which can be attributed to the proximity-induced gap. We have also observed the conductances showing the features of normal conducting and/or low-Tc phases. Our tunneling data can be explained by the proximity effect combined with the bulk multiple-gap features.

Original languageEnglish
Pages (from-to)1902-1913
Number of pages12
JournalJournal of the Physical Society of Japan
Volume73
Issue number7
DOIs
Publication statusPublished - Jul 1 2004
Externally publishedYes

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proximity
critical temperature
conduction
temperature dependence
spectroscopy

Keywords

  • Break junction
  • MgB<inf>2</inf>
  • Multiplegap structure
  • Superconductivity
  • The correlated two-gap model
  • Tunneling spectroscopy

ASJC Scopus subject areas

  • Physics and Astronomy(all)

Cite this

Multiple-gap features from break-junction tunneling in the superconducting MgB2. / Takasaki, Tomoaki; Ekino, Toshikazu; Muranaka, Takahiro; Ichikawa, Takayuki; Fujii, Hironobu; Akimitsu, Jun.

In: Journal of the Physical Society of Japan, Vol. 73, No. 7, 01.07.2004, p. 1902-1913.

Research output: Contribution to journalArticle

Takasaki, Tomoaki ; Ekino, Toshikazu ; Muranaka, Takahiro ; Ichikawa, Takayuki ; Fujii, Hironobu ; Akimitsu, Jun. / Multiple-gap features from break-junction tunneling in the superconducting MgB2. In: Journal of the Physical Society of Japan. 2004 ; Vol. 73, No. 7. pp. 1902-1913.
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