Thermodynamic study of gap structure and pair-breaking effect by magnetic field in the heavy-fermion superconductor CeCu2Si2

Abstract

This paper presents the results of specific-heat and magnetization measurements, in particular their field-orientation dependence, on the first discovered heavy-fermion superconductor CeCu${}_2$Si${}_2$ ($T_{\mathrm{c}}\sim 0.6$ K). We discuss the superconducting gap structure and the origin of the anomalous pair-breaking phenomena, leading e.g., to the suppression of the upper critical field $H_{c2}$, found in the high-field region. The data show that the anomalous pair breaking becomes prominent below about 0.15 K in any field direction, but occurs closer to $H_{c2}$ for $H\parallel c$. The presence of this anomaly is confirmed by the fact that the specific-heat and magnetization data satisfy standard thermodynamic relations. Concerning the gap structure, field-angle dependences of the low-temperature specific heat within the $ab$ and $ac$ planes do not show any evidence for gap nodes. From microscopic calculations in the framework of a two-band full-gap model, the power-law-like temperature dependences of $C$ and $1/T_1$, reminiscent of nodal superconductivity, have been reproduced reasonably. These facts further support multiband full-gap superconductivity in CeCu${}_2$Si${}_2$.

10 pages, 8 figures, published in Phys. Rev. B

References in corpus (21)

• Angular Position of Nodes in the Superconducting Gap of Quasi-2D Heavy-Fermion Superconductor CeCoIn_5
• Phenomenological two-gap model for the specific heat of MgB_2
• Magnetically driven superconductivity in CeCu2Si2
• Anisotropic thermodynamics of d-wave superconductors in the vortex state
• Sign reversal of field-angle resolved heat capacity oscillations in a heavy fermion superconductor CeCoIn${}_5$ and $d_{x^2-y^2}$ pairing symmetry
• Possible Multiple Gap Superconductivity with Line Nodes in Heavily Hole-Doped Superconductor KFe2As2 Studied by 75As-NQR and Specific Heat
• Vortex Contribution to Specific Heat of Dirty $d$-Wave Superconductors: Breakdown of Scaling
• Multiband superconductivity with unexpected deficiency of nodal quasiparticles in CeCu2Si2
• Field Dependence of Electronic Specific Heat in Two-Band Superconductors
• Feedback spin resonance in superconducting CeCu${}_2$Si${}_2$ and CeCoIn${}_5$
• Field dependence of the zero energy density of states around vortices in an anisotropic gap superconductor
• Nuclear magnetic relaxation and superfluid density in Fe-pnictide superconductors: An anisotropic \pm s-wave scenario
• Emergent loop-nodal s${}_{\pm }$-wave superconductivity in CeCu${}_2$Si${}_2$: similarities to the iron-based superconductors
• Thermal conductivity evidence for d_{x^2-y^2} pairing symmetry in the heavy-fermion CeIrIn5 superconductor
• Superconducting gap and vortex lattice of the heavy fermion compound CeCu_2Si_2
• Evidence for chiral d-wave superconductivity in URu2Si2 from the field-angle variation of its specific heat
• Probing the nodal gap in the pressure-induced heavy fermion superconductor CeRhIn5
• Multiband Superconductivity in KFe2As2: Evidence for one Isotropic and several Liliputian Energy Gaps
• Thermodynamic Study of Nodal Structure and Multiband Superconductivity of KFe2As2
• Superconducting gap structure of CeIrIn5 from field-angle-resolved measurements of its specific heat
• Hidden Crossover Phenomena in Strongly Pauli Limited Multiband Superconductors ---Application to CeCu${}_2$Si${}_2$

Cited by in corpus (19)

• Fully gapped superconductivity with no sign change in the prototypical heavy-fermion CeCu2Si2
• Observation of antiferromagnetic order as odd-parity multipoles inside the superconducting phase in CeRh${}_2$As${}_2$
• Evidence for the presence of the Fulde-Ferrell-Larkin-Ovchinnikov state in CeCu${}_2$Si${}_2$ revealed using ${}^{63}$Cu NMR
• Gap symmetry of the heavy fermion superconductor CeCu${}_2$Si${}_2$ at ambient pressure
• Unconventional density waves and superconductivities in Fe-based superconductors and other strongly correlated electron systems
• Unconventional fully-gapped superconductivity in the heavy-fermion metal CeCu${}_2$Si${}_2$
• Fully gapped s-wave superconductivity enhanced by magnetic criticality in heavy fermion system
• Hexadecapole fluctuation mechanism for s-wave heavy fermion superconductor CeCu2Si2: Interplay between intra- and inter-orbital Cooper pairs
• The Dominant Role of Critical Valence Fluctuations on High $T_{\mathrm{c}}$ Superconductivity in Heavy Fermions
• Magnetic and superconducting properties on S-type single-crystal CeCu${}_2$Si${}_2$ probed by ${}^{63}$Cu nuclear magnetic resonance and nuclear quadrupole resonance
• Plain $s$-wave superconductivity near the magnetic criticality: Enhancement of attractive electron-boson coupling vertex corrections
• High-energy magnetic excitations from heavy quasiparticles in CeCu${}_2$Si${}_2$
• Exposing the odd-parity superconductivity in CeRh${}_2$As${}_2$ with hydrostatic pressure
• An emerging global picture of heavy fermion physics
• Observation of two critical points linked to the high field phase B in CeCu2Si2
• Novel attractive pairing interaction in strongly correlated superconductors
• Classification of multiorbital superconducting state based on augmented multipoles
• Revealing sign-reversal $s^{+-}$-wave pairing by quasiparticle interference in the heavy-fermion superconductor CeCu${}_2$Si${}_2$
• Anomalous impurity effect in the heavy-fermion superconductor CeCu2Si2