As-NMR/NQR study of CaFe2As2 under pressure

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

doi:10.1143/JPSJS.80SA.SA116

As-NMR/NQR study of CaFe₂As₂ under pressure

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

School of Science

Research output: Contribution to journal › Article › peer-review

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 T_c 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 language	English
Article number	SA116
Journal	journal of the physical society of japan
Volume	80
Issue number	SUPPL. A
DOIs	https://doi.org/10.1143/JPSJS.80SA.SA116
Publication status	Published - Jul 2011

Keywords

CaFeAs
NMR/NQR
Pressure
Quantum critical point
Superconductivity

ASJC Scopus subject areas

Physics and Astronomy(all)

Access to Document

10.1143/JPSJS.80SA.SA116

Cite this

@article{7443e82772dd4c4097a59c3de7825d56,

title = "As-NMR/NQR study of CaFe2As2 under pressure",

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.",

keywords = "CaFeAs, NMR/NQR, Pressure, Quantum critical point, Superconductivity",

author = "Shinji Kawasaki and Toshihide Oka and Takahisa Tabuchi and Wang, {X. F.} and Chen, {X. H.} and Zheng, {Guo Qing}",

note = "Funding Information: S.K. thanks Y. Fuseya, H. Kohno, and K. Miyake for useful discussion and helpful comments. This work was supported by a Grant-in-Aid for Scientific Research on Innovative Areas “Heavy Electrons” (No. 21102514 ) of The Ministry of Education, Culture, Sports, Science, and Technology, Japan.",

year = "2011",

month = jul,

doi = "10.1143/JPSJS.80SA.SA116",

language = "English",

volume = "80",

journal = "journal of the physical society of japan",

issn = "0031-9015",

publisher = "Physical Society of Japan",

number = "SUPPL. A",

}

TY - JOUR

T1 - As-NMR/NQR study of CaFe2As2 under pressure

AU - Kawasaki, Shinji

AU - Oka, Toshihide

AU - Tabuchi, Takahisa

AU - Wang, X. F.

AU - Chen, X. H.

AU - Zheng, Guo Qing

N1 - Funding Information: S.K. thanks Y. Fuseya, H. Kohno, and K. Miyake for useful discussion and helpful comments. This work was supported by a Grant-in-Aid for Scientific Research on Innovative Areas “Heavy Electrons” (No. 21102514 ) of The Ministry of Education, Culture, Sports, Science, and Technology, Japan.

PY - 2011/7

Y1 - 2011/7

N2 - 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.

AB - 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.

KW - CaFeAs

KW - NMR/NQR

KW - Pressure

KW - Quantum critical point

KW - Superconductivity

UR - http://www.scopus.com/inward/record.url?scp=80052405306&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=80052405306&partnerID=8YFLogxK

U2 - 10.1143/JPSJS.80SA.SA116

DO - 10.1143/JPSJS.80SA.SA116

M3 - Article

AN - SCOPUS:80052405306

SN - 0031-9015

VL - 80

JO - journal of the physical society of japan

JF - journal of the physical society of japan

IS - SUPPL. A

M1 - SA116

ER -