Related papers: Fully gapped $d$-wave superconductivity in CeCu$_2…
The heavy-fermion metal CeCu$_2$Si$_2$ was the first discovered unconventional, non-phonon-mediated superconductor, and for a long time was believed to exhibit single-band $d$-wave superconductivity, as inferred from various measurements…
Recent observations of two nodeless gaps in superconducting CeCu$_2$Si$_2$ have raised intensive debates on its exact gap symmetry, while a satisfactory theoretical basis is still lacking. Here we propose a phenomenological approach to…
Superconductivity in the heavy-fermion compound CeCu2Si2 is a prototypical example of Cooper pairs formed by strongly correlated electrons. For more than 30 years, it has been believed to arise from nodal d-wave pairing mediated by a…
Multiband superconductivity with dominant two-gap features are recently proposed to challenge the earlier accepted nodal $d$-wave pairing in the first unconventional superconductor CeCu$_{2}$Si$_{2}$. Here we obtain multiband Fermi-surface…
A key aspect of unconventional pairing by the antiferromagnetic spin-fluctuation mechanism is that the superconducting energy gap must have opposite sign on different parts of the Fermi surface. Recent observations of non-nodal gap…
Heavy-fermion superconductors are prime candidates for novel electron-pairing states due to the spin-orbital coupled degrees of freedom and electron correlations. Superconductivity in CeCu$_2$Si$_2$ discovered in 1979, which is a prototype…
In exotic superconductors including high-$T_c$ copper-oxides, the interactions mediating electron Cooper-pairing are widely considered to have a magnetic rather than the conventional electron-phonon origin. Interest in such exotic pairing…
The heavy-fermion superconductor CeCu$_{2}$Si$_{2}$ exhibits two-band, $d$-wave superconductivity with a finite energy gap over the whole Fermi surface around the magnetic instability where 4$f$ antiferrerromagnetic order is suppressed. In…
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$_2$ ($T_{\rm c} \sim 0.6$ K). We discuss the…
Understanding the origin of superconductivity in strongly correlated electron systems continues to be at the forefront of unsolved problems in all of physics. Among the heavy f-electron systems, CeCoIn5 is one of the most fascinating, as it…
The order parameter and pairing mechanism for superconductivity in heavy fermion compounds are still poorly understood. Scanning tunneling microscopy and spectroscopy at ultra-low temperatures can yield important information about the…
The first heavy fermion superconductor CeCu$_2$Si$_2$ has not revealed all its striking mysteries yet. At high pressures, superconductivity is supposed to be mediated by valence fluctuations, in contrast to ambient pressure, where spin…
Thermal conductivity and specific heat were measured in the superconducting state of the heavy fermion material Ce_{1-x}La_{x}CoIn_{5}. With increasing impurity concentration x, the suppression of T_{c} is accompanied by the increase in the…
The thermal conductivity of the heavy-fermion superconductor CeCoIn_5 has been studied in a magnetic field rotating within the 2D planes. A clear fourfold symmetry of the thermal conductivity which is characteristic of a superconducting gap…
According to [M.A. Tanatar et al., Phys. Rev. Lett. 95, 067002 (2005)], in a multi-band d-wave superconductor CeCoIn5 electrons remain partially uncondensed. Interactions must induce superconducting order on all Fermi surfaces. We calculate…
Recent observations of two nodeless gaps in superconducting CeCu$_2$Si$_2$ have raised intensive debates as to its exact gap structure of either sign-reversal ($s^{+-}$) or sign-preserving ($s^{++}$) pairing. Here we investigate the…
Magnetic fluctuations is the leading candidate for pairing in cuprate, iron-based and heavy fermion superconductors. This view is challenged by the recent discovery of nodeless superconductivity in CeCu$_2$Si$_2$, and calls for a detailed…
Temperature dependence of the London penetration depth $\lambda$ measured in single crystals of CeCoIn$_5$ is interpreted as caused by a strong pair-breaking scattering that makes the superconductivity in this compound gapless. For a…
In heavy-fermion superconductors, it is widely believed that the superconducting gap function has sign-reversal due to the strong electron correlation. However, recently discovered fully-gapped s-wave superconductivity in CeCu2Si2 has…
In this paper the low-temperature properties of two isostructural canonical heavy-fermion compounds are contrasted with regards to the interplay between antiferromagnetic (AF) quantum criticality and superconductivity. For CeCu$_2$Si$_2$,…