As-NMR/NQR study of CaFe2As2 under pressure

Shinji Kawasaki, Toshihide Oka, Takahisa Tabuchi, X. F. Wang, X. H. Chen, Guo-Qing Zheng

Research output: Contribution to journalArticle

Abstract

75As-zero-field nuclear magnetic resonance (NMR) and nuclear quadrupole resonance (NQR) measurements are performed on CaFe2As 2 under pressure. At P = 4.7 and 10.8 kbar, the temperature dependence of nuclear-spin-lattice relaxation rate (1/T1) measured at tetragonal phase show no coherence peak just below Tc and decrease with decreasing temperature. The superconductivity is of gapless at P = 4.7 kbar but evolves to multiple gaps at P = 10.8 kbar. We find that the superconductivity appears near a quantum critical point. Both electron correlation and superconductivity disappear in the collapsed tetragonal phase. A systematic study under pressure indicates that electron correlations play a vital role in forming Cooper pairs in this compound.

Original languageEnglish
Article numberSA116
JournalJournal of the Physical Society of Japan
Volume80
Issue numberSUPPL. A
DOIs
Publication statusPublished - Jul 2011

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nuclear quadrupole resonance
superconductivity
nuclear magnetic resonance
spin-lattice relaxation
nuclear spin
critical point
electrons
temperature dependence
temperature

Keywords

  • CaFeAs
  • NMR/NQR
  • Pressure
  • Quantum critical point
  • Superconductivity

ASJC Scopus subject areas

  • Physics and Astronomy(all)

Cite this

As-NMR/NQR study of CaFe2As2 under pressure. / Kawasaki, Shinji; Oka, Toshihide; Tabuchi, Takahisa; Wang, X. F.; Chen, X. H.; Zheng, Guo-Qing.

In: Journal of the Physical Society of Japan, Vol. 80, No. SUPPL. A, SA116, 07.2011.

Research output: Contribution to journalArticle

Kawasaki, Shinji ; Oka, Toshihide ; Tabuchi, Takahisa ; Wang, X. F. ; Chen, X. H. ; Zheng, Guo-Qing. / As-NMR/NQR study of CaFe2As2 under pressure. In: Journal of the Physical Society of Japan. 2011 ; Vol. 80, No. SUPPL. A.
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