Superconducting energy gap from break-junction tunneling spectroscopy in the ternary silicide CaAlSi

S. Kuroiwa, T. Takasaki, T. Ekino, Jun Akimitsu

Research output: Contribution to journalArticle

7 Citations (Scopus)

Abstract

Tunneling spectroscopy using a break-junction technique has been conducted to determine the superconducting gap structure of the ternary silicide-layered superconductor CaAlSi with and without superstructure. We find that the tunneling conductance in CaAlSi shows a single gap feature, which can be described by the BCS density of states. The gap size Δ obtained from the tunneling conductance in CaAlSi without superstructure is estimated to be approximately 1.0 meV, corresponding to a weak-coupling gap ratio. On the other hand, for a specimen with superstructure, the largest gap, Δ=1.5 meV, significantly deviates from the BCS value, indicating strong-coupling superconductivity. These results demonstrate systematic variations in the pairing interaction with superstructure formations, which are consistent with heat capacity measurements.

Original languageEnglish
Article number104508
JournalPhysical Review B - Condensed Matter and Materials Physics
Volume76
Issue number10
DOIs
Publication statusPublished - Sep 12 2007
Externally publishedYes

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Superconductivity
Superconducting materials
Specific heat
Energy gap
Spectroscopy
spectroscopy
superconductivity
specific heat
interactions

ASJC Scopus subject areas

  • Condensed Matter Physics

Cite this

Superconducting energy gap from break-junction tunneling spectroscopy in the ternary silicide CaAlSi. / Kuroiwa, S.; Takasaki, T.; Ekino, T.; Akimitsu, Jun.

In: Physical Review B - Condensed Matter and Materials Physics, Vol. 76, No. 10, 104508, 12.09.2007.

Research output: Contribution to journalArticle

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