Related papers: Fully gapped $d$-wave superconductivity in CeCu$_2…
The recent observation of fully-gapped superconductivity in Yb doped CeCoIn5 poses a paradox, for the disappearance of nodes suggests that they are accidental, yet d-wave symmetry with protected nodes is we ll established by experiment.…
We theoretically study the effect of a nonmagnetic impurity in heavy fermion superconductor CeCoIn$_{5}$ within a realistic band model and the T-matrix approximation approach. By considering two known possible pairing symmetry candidates…
The superconducting order parameter of the first heavy-fermion superconductor CeCu2Si2 is currently under debate. A key ingredient to understand its superconductivity and physical properties is the quasiparticle dispersion and Fermi…
The nature of the pairing state in iron-based superconductors is the subject of much debate. Here we argue that in one material, the stoichiometric iron pnictide KFe2As2, there is overwhelming evidence for a d-wave pairing state,…
CaSb2 is a topological nodal-line semimetal that becomes superconducting below 1.6 K, providing an ideal platform to investigate the interplay between topologically nontrivial electronic bands and superconductivity. In this work, we…
Recent observations of contradictory impurity effect in the heavy-fermion superconductor CeCu2Si2 at ambient pressure have hindered the identification of its pairing symmetry. Here we perform theoretical analyses with both intraband and…
Taking advantage of a novel multiprobe setup we have measured, on a unique sample, the ac-magnetic susceptibility, the resistivity, the ac-specific heat and the thermopower of the superconductor heavy fermion CeCu$_{2}$Si$_{2}$ under…
Low-temperature (T) heat-capacity measurements under hydrostatic pressure of up to p=2.1 GPa have been performed on single-crystalline CeCu2Si2. A broad superconducting (SC) region exists in the T-p phase diagram. In the low-pressure region…
CeCoIn5 is a heavy fermion superconductor with strong similarities to the high-Tc cuprates, including quasi-two-dimensionality, proximity to antiferromagnetism, and probable d-wave pairing arising from a non-Fermi-liquid normal state.…
The structure of the superconducting gap provides important clues on the symmetry of the order parameter and the pairing mechanism. The presence of nodes in the gap function imposed by symmetry implies an unconventional order parameter,…
We report a comprehensive TF-muSR study of TiSe_2Cu_2. The magnetic penetration depth was found to saturate at low temperature as expected in an s-wave SC. As x is increased we find that the superfluid density increases and the size of the…
Recent experiments in multiband Fe-based and heavy-fermion superconductors have challenged the long-held dichotomy between simple $s$- and $d$-wave spin-singlet pairing states. Here, we advance several time-reversal-invariant irreducible…
We report on the basis of Cu-NQR measurements that superconductivity (SC) and antiferromagnetism (AF) coexist on a microscopic level in CeCu_{2}(Si_{1-x}Ge_{x})_{2}, once a tiny amount of 1%Ge (x = 0.01) is substituted for Si. This…
We propose an effective single-band model for the newly discovered iron selenide superconductors A$_x$Fe$_{2-y}$Se$_2$ (A=Tl,K,Rb,Cs). Based on this minimum model and the random phase approximation, the $d_{x^2-y^2}$ pairing symmetry is…
Phase-sensitive tests of pairing symmetry have provided strong evidence for predominantly d-wave pairing symmetry in both hole- and electron-doped high-Tc cuprate superconductors. Temperature dependent measurements in YBCO indicate that the…
Quasi-two dimensional CeIrIn5 contains two distinct domes with different heavy fermion superconducting states in its phase diagram. Here we pinned down the superconducting gap structure of CeIrIn5 in the second dome, located away from the…
Angle-resolved photoemission spectroscopy measurements on the recently discovered superconduc- tors in the KFe2Se2 family with critical temperatures up to - 33K suggest that no Fermi pockets of hole character centered on the {\Gamma} point…
We have investigated the doping dependence of the penetration depth vs. temperature in electron doped Pr$_{2-x}$Ce$_x$CuO$_{4-\delta}$ using a model which assumes the uniform coexistence of (mean-field) antiferromagnetism and…
The origin of unconventional superconductivity, including high-temperature and heavy-fermion superconductivity, is still a matter of controversy. Spin excitations instead of phonons are thought to be responsible for the formation of Cooper…
The CuIr$_{2-x}$Ru$_x$Te$_4$ superconductors (with a $T_c$ around 2.8 K) can host charge-density waves, whose onset and interplay with superconductivity are not well known at a microscopic level. Here, we report a comprehensive study of the…