High pressure NQR measurement in CeCu2Si2 up to sudden disappearance of superconductivity

Kenji Fujiwara; Yoshiki Hata; Keigo Kobayashi; Kiyotaka Miyoshi; Jun Takeuchi; Yoshiyuki Shimaoka; Hisashi Kotegawa; Tatsuo C. Kobayashi; Christoph Geibel; Frank Steglich

doi:10.1143/JPSJ.77.123711

High pressure NQR measurement in CeCu₂Si₂ up to sudden disappearance of superconductivity

Kenji Fujiwara, Yoshiki Hata, Keigo Kobayashi, Kiyotaka Miyoshi, Jun Takeuchi, Yoshiyuki Shimaoka, Hisashi Kotegawa, Tatsuo C. Kobayashi, Christoph Geibel, Frank Steglich

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

63 Citations (Scopus)

Abstract

We report the results of ⁶³Cu nuclear quadrupole resonance (NQR) measurements on CeCu₂Si₂ under high pressures up to 4.8 GPa. Enhanced spin fluctuations due to quantum criticality at ambient pressure are drastically suppressed with increasing pressure, whereas T_c increases from 0.7 K at ambient pressure to 1.64 K at 4.2 GPa. We have found that bulk superconductivity suddenly disappears at 4.8 GPa accompanied with a rapid decrease in the density of states at the Fermi level. The nuclear spin-lattice relaxation rate 1/T₁ at 4.2 GPa reveals that anisotropic superconductivity in the strong-coupling regime is realized even under high pressure far from the antiferromagnetic critical point. Superconductivity under high pressure is unconventional in origin, but the spin fluctuation scenario is not likely to be applicable.

Original language	English
Article number	123711
Journal	journal of the physical society of japan
Volume	77
Issue number	12
DOIs	https://doi.org/10.1143/JPSJ.77.123711
Publication status	Published - Dec 2008

Keywords

CeCuSi
High pressure
NQR
Superconductivity

ASJC Scopus subject areas

Physics and Astronomy(all)

Access to Document

10.1143/JPSJ.77.123711

Cite this

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title = "High pressure NQR measurement in CeCu2Si2 up to sudden disappearance of superconductivity",

abstract = "We report the results of 63Cu nuclear quadrupole resonance (NQR) measurements on CeCu2Si2 under high pressures up to 4.8 GPa. Enhanced spin fluctuations due to quantum criticality at ambient pressure are drastically suppressed with increasing pressure, whereas Tc increases from 0.7 K at ambient pressure to 1.64 K at 4.2 GPa. We have found that bulk superconductivity suddenly disappears at 4.8 GPa accompanied with a rapid decrease in the density of states at the Fermi level. The nuclear spin-lattice relaxation rate 1/T1 at 4.2 GPa reveals that anisotropic superconductivity in the strong-coupling regime is realized even under high pressure far from the antiferromagnetic critical point. Superconductivity under high pressure is unconventional in origin, but the spin fluctuation scenario is not likely to be applicable.",

keywords = "CeCuSi, High pressure, NQR, Superconductivity",

author = "Kenji Fujiwara and Yoshiki Hata and Keigo Kobayashi and Kiyotaka Miyoshi and Jun Takeuchi and Yoshiyuki Shimaoka and Hisashi Kotegawa and Kobayashi, {Tatsuo C.} and Christoph Geibel and Frank Steglich",

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doi = "10.1143/JPSJ.77.123711",

language = "English",

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T1 - High pressure NQR measurement in CeCu2Si2 up to sudden disappearance of superconductivity

AU - Fujiwara, Kenji

AU - Hata, Yoshiki

AU - Kobayashi, Keigo

AU - Miyoshi, Kiyotaka

AU - Takeuchi, Jun

AU - Shimaoka, Yoshiyuki

AU - Kotegawa, Hisashi

AU - Kobayashi, Tatsuo C.

AU - Geibel, Christoph

AU - Steglich, Frank

PY - 2008/12

Y1 - 2008/12

N2 - We report the results of 63Cu nuclear quadrupole resonance (NQR) measurements on CeCu2Si2 under high pressures up to 4.8 GPa. Enhanced spin fluctuations due to quantum criticality at ambient pressure are drastically suppressed with increasing pressure, whereas Tc increases from 0.7 K at ambient pressure to 1.64 K at 4.2 GPa. We have found that bulk superconductivity suddenly disappears at 4.8 GPa accompanied with a rapid decrease in the density of states at the Fermi level. The nuclear spin-lattice relaxation rate 1/T1 at 4.2 GPa reveals that anisotropic superconductivity in the strong-coupling regime is realized even under high pressure far from the antiferromagnetic critical point. Superconductivity under high pressure is unconventional in origin, but the spin fluctuation scenario is not likely to be applicable.

AB - We report the results of 63Cu nuclear quadrupole resonance (NQR) measurements on CeCu2Si2 under high pressures up to 4.8 GPa. Enhanced spin fluctuations due to quantum criticality at ambient pressure are drastically suppressed with increasing pressure, whereas Tc increases from 0.7 K at ambient pressure to 1.64 K at 4.2 GPa. We have found that bulk superconductivity suddenly disappears at 4.8 GPa accompanied with a rapid decrease in the density of states at the Fermi level. The nuclear spin-lattice relaxation rate 1/T1 at 4.2 GPa reveals that anisotropic superconductivity in the strong-coupling regime is realized even under high pressure far from the antiferromagnetic critical point. Superconductivity under high pressure is unconventional in origin, but the spin fluctuation scenario is not likely to be applicable.

KW - CeCuSi

KW - High pressure

KW - NQR

KW - Superconductivity

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