High-resolution ac-calorimetry studies of the quasi-two-dimensional organic superconductor κ-(BEDT-TTF)2Cu(NCS)2

J. Müller; M. Lang; R. Helfrich; F. Steglich; T. Sasaki

High-resolution ac-calorimetry studies of the quasi-two-dimensional organic superconductor κ-(BEDT-TTF)₂Cu(NCS)₂

J. Müller, M. Lang, R. Helfrich, F. Steglich, T. Sasaki

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

Abstract

We report high-resolution specific-heat measurements on the quasi-two-dimensi-onal organic superconductorκ(BEDTTTF)₂Cu(NCS)₂, performed by using a sensitive ac-modulation technique. The main observations are (i) a discontinuity at T_c much in excess of what is expected for a weak-coupling BCS superconductor and (ii) a quasiparticle contribution to the specific heat with an exponentially weak temperature dependence at T ≪T_c. The latter finding is incompatible with an order parameter that vanishes at certain parts of the Fermi surface. The data for T≥T_c can be well described by a strong-coupling extension of the BCS theorythe α-modelsimilar to what has been recently found for the κ-(BEDT-TTF)₂Cu[N(CN)₂]Br salt [Elsinger et al., Phys. Rev. Lett. 84, 6098 (2000)].

Original language	English
Article number	140509
Pages (from-to)	1405091-1405094
Number of pages	4
Journal	Physical Review B - Condensed Matter and Materials Physics
Volume	65
Issue number	14
Publication status	Published - 2002 Apr 1
Externally published	Yes

ASJC Scopus subject areas

Electronic, Optical and Magnetic Materials
Condensed Matter Physics

Cite this

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title = "High-resolution ac-calorimetry studies of the quasi-two-dimensional organic superconductor κ-(BEDT-TTF)2Cu(NCS)2",

abstract = "We report high-resolution specific-heat measurements on the quasi-two-dimensi-onal organic superconductorκ(BEDTTTF)2Cu(NCS)2, performed by using a sensitive ac-modulation technique. The main observations are (i) a discontinuity at Tc much in excess of what is expected for a weak-coupling BCS superconductor and (ii) a quasiparticle contribution to the specific heat with an exponentially weak temperature dependence at T ≪Tc. The latter finding is incompatible with an order parameter that vanishes at certain parts of the Fermi surface. The data for T≥Tc can be well described by a strong-coupling extension of the BCS theorythe α-modelsimilar to what has been recently found for the κ-(BEDT-TTF)2Cu[N(CN)2]Br salt [Elsinger et al., Phys. Rev. Lett. 84, 6098 (2000)].",

author = "J. M{\"u}ller and M. Lang and R. Helfrich and F. Steglich and T. Sasaki",

year = "2002",

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language = "English",

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T1 - High-resolution ac-calorimetry studies of the quasi-two-dimensional organic superconductor κ-(BEDT-TTF)2Cu(NCS)2

AU - Müller, J.

AU - Lang, M.

AU - Helfrich, R.

AU - Steglich, F.

AU - Sasaki, T.

PY - 2002/4/1

Y1 - 2002/4/1

N2 - We report high-resolution specific-heat measurements on the quasi-two-dimensi-onal organic superconductorκ(BEDTTTF)2Cu(NCS)2, performed by using a sensitive ac-modulation technique. The main observations are (i) a discontinuity at Tc much in excess of what is expected for a weak-coupling BCS superconductor and (ii) a quasiparticle contribution to the specific heat with an exponentially weak temperature dependence at T ≪Tc. The latter finding is incompatible with an order parameter that vanishes at certain parts of the Fermi surface. The data for T≥Tc can be well described by a strong-coupling extension of the BCS theorythe α-modelsimilar to what has been recently found for the κ-(BEDT-TTF)2Cu[N(CN)2]Br salt [Elsinger et al., Phys. Rev. Lett. 84, 6098 (2000)].

AB - We report high-resolution specific-heat measurements on the quasi-two-dimensi-onal organic superconductorκ(BEDTTTF)2Cu(NCS)2, performed by using a sensitive ac-modulation technique. The main observations are (i) a discontinuity at Tc much in excess of what is expected for a weak-coupling BCS superconductor and (ii) a quasiparticle contribution to the specific heat with an exponentially weak temperature dependence at T ≪Tc. The latter finding is incompatible with an order parameter that vanishes at certain parts of the Fermi surface. The data for T≥Tc can be well described by a strong-coupling extension of the BCS theorythe α-modelsimilar to what has been recently found for the κ-(BEDT-TTF)2Cu[N(CN)2]Br salt [Elsinger et al., Phys. Rev. Lett. 84, 6098 (2000)].

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High-resolution ac-calorimetry studies of the quasi-two-dimensional organic superconductor κ-(BEDT-TTF)₂Cu(NCS)₂

Abstract

ASJC Scopus subject areas

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