Related papers: Superconductivity: Exotic Commonalities in Phase a…
Inelastic neutron scattering for Nd$_{2-x}$Ce$_x$CuO$_{4+\delta}$ near optimal doping ($x \approx 0.155$, $T_{c} = 25 \mathrm{K}$) reveals that the dynamic magnetic susceptibility at the antiferromagnetic zone center exhibits two…
The discovery of high-temperature superconductivity in Fe-based compounds [1,2] has triggered numerous investigations on the interplay between superconductivity and magnetism [3] and, more recently, on the enhancement of transition…
The presence of macroscopic phase separation into superconducting and magnetic phases in LaFeAsO$_{1-x}$F$_x$ (LFAOF) and CaFe$_{1-x}$Co$_x$AsF (CFCAF) is demonstrated by muon spin rotation (muSR) measurement across their phase boundaries…
Muon spin relaxation ($\mu$SR) measurements on the new layered cobalt oxide superconductor Na$_{0.35}$CoO$_{2}\cdot$1.3H$_{2}$O and its parent, non-superconducting compounds, have revealed unconventional nature of superconductivity through:…
We report density functional calculations of the electronic structure, Fermi surface, phonon spectrum, magnetism and electron-phonon coupling for the superconducting phase FeSe, as well as the related compounds FeS and FeTe. We find that…
Superconductivity arises in the layered iron-pnictide compounds when magnetic long range order disappears. We use first principles density functional methods to study magnetic arrangements that may compete with long range order near the…
Superconducting high-entropy alloys (HEAs) are a newly burgeoning field of unconventional superconductors and raise intriguing questions about the presence of superconductivity in highly disordered systems, which lack regular phonon modes.…
Since its discovery, iron-based superconductivity has been known to develop near an antiferromagnetic order, but this paradigm fails in the iron chalcogenide FeSe, whose single-layer version holds the record for the highest superconducting…
Study of superconductivity in layered iron-based materials was initiated in 2006 by Hosono's group, and boosted in 2008 by the superconducting transition temperature, Tc, of 26 K in LaFeAsO1-xFx. Since then, enormous researches have been…
$^{75}$As nuclear magnetic resonance (NMR) measurements carried out on underdoped, non-superconducting Ca$_{10}$(Pt$_3$As$_8$)(Fe$_2$As$_2$)$_5$ reveal physical properties that are similar but not identical to the 122 superconductor parent…
FeSe$_{1-x}$S$_{x}$ superconductors are commonly considered layered van der Waals materials with negligible inter-layer coupling. Here, using inelastic neutron scattering to study spin excitations in single-crystal samples, we reveal that…
Intermetallic compounds containing f-electron elements display a wealth of superconducting phases, that are prime candidates for unconventional pairing with complex order parameter symmetries. For instance, superconductivity has been found…
In this review, we present a summary of the results on single crystal growth of two types of iron-chalcogenide superconductors, Fe(1+y)Te(1-x)Se(x) (11), and A(x)Fe(2-y)Se(2) (A= K, Rb, Cs, Tl, Tl/K, Tl/Rb), using Bridgman, zone-melting,…
The systematic pressure shifts of T_c were investigated in the whole phase diagram of the FeAs-based superconducting compound K_xSr_{1-x}Fe_2As_2. Different regions, arising from corresponding responses of T$_c$ to pressure (dT_c/dp>0, =0,…
Very recently a new family of layered materials, containing BiS2 planes was discovered to be superconducting at temperatures up to Tc=10 K, raising questions about the mechanism of superconductivity in these systems. Here, we present…
High-quality single crystals of K0.8Fe2Se1.4S0.4 are successfully synthesized by self-flux method with the superconducting transition temperatures Tconset = 32.8 K and Tczero = 31.2 K. In contrast to external pressure effect on…
We report $^{31}$P- and $^{75}$As-NMR studies on (Ca$_4$Al$_2$O$_{6}$)Fe$_2$(As$_{1-x}$P$_x$)$_2$ with an isovalent substitution of P for As. We present the novel evolution of emergent phases that the nodeless superconductivity (SC) in…
We review neutron scattering investigations of the crystal structures, magnetic structures, and spin dynamics of the iron-based RFe(As,P)O (R=La, Ce, Pr, Nd), (Ba,Sr,Ca)Fe2As2, and Fe1+x(Te-Se) systems. On cooling from room temperature all…
In this review article we present a survey of unconventional superconductors and their coexistence behaviour with magnetism. We focus on Ce- and U-based heavy fermion superconductors, in addition we discuss the rare earth borocarbide and…
The recently discovered high-temperature superconductivity in doped quaternary iron oxypnictides correlates experimentally with a magnetic instability. We have used first-principles calculations to determine a magnetic phase diagram of…