Related papers: Spin resonance in the d-wave superconductor CeCoIn…

The heavy-fermion superconductor CeCoIn5 is the first material, where different experimental probes show strong evidence pointing to the realization of the Fulde-Ferrell-Larkin-Ovchinnikov (FFLO) state. The inhomogeneous superconducting…

We study the spin dynamics in underdoped cuprates at low temperatures by considering them as quasi two dimensional d-wave superconductors (dSC) with strong phase fluctuations. An effective theory of spin degrees of freedom of nodal…

Superconductivity appears to compete against the spin-density-wave in Fe pnictides. However, optimally cobalt doped samples show a quasi-two-dimensional spin excitation centered at the (0.5, 0.5, L) wavevector, "the spin resonance peak",…

It is shown by detailed inelastic neutron scattering experiments that the gapped collective magnetic excitation of the unconventional superconductor CeCoIn$_{5}$, the spin resonance mode, is incommensurate and that the corresponding…

We report results of $^{59}$Co nuclear magnetic resonance measurements on a single crystal of superconducting PuCoGa5 in its normal state. The nuclear spin-lattice relaxation rates and the Knight shifts as a function of temperature reveal…

High-temperature superconductivity in both the copper-oxide and the iron-pnictide/chalcogenide systems occurs in close proximity to antiferromagnetically ordered states. Neutron scattering has been an essential technique for characterizing…

The newly discovered superconductor La(O,F)FeAs (Tc = 26 K) was investigated using the neutron scattering technique. No spin-density-wave (SDW) order was observed in the normal state nor in the superconducting state, both with and without…

Magnetic fluctuations in the molecular-intercalated FeSe superconductor Li{x}(ND2){y}(ND3){1-y}Fe2Se2 (Tc = 43K) have been measured by inelastic neutron scattering from a powder sample. The strongest magnetic scattering is observed at a…

Recent thermal conductivity measurements in the heavy-fermion compound CeIrIn_5 indicate that its superconducting order parameter is very different from CeCoIn_5. Here we show that these experiments are consistent with chiral d-wave…

The nature of the magnetic correlations in Fe-based superconductors remains a matter of controversy. To address this issue, we use inelastic neutron scattering to characterize the strength and temperature dependence of low-energy spin…

Neutron scattering is used to characterise the magnetism of the vortices for the optimally doped high-temperature superconductor La(2-x)Sr(x)CuO(4) (x=0.163) in an applied magnetic field. As temperature is reduced, low frequency spin…

The in-plane infrared response of the high-Tc cuprate superconductors was studied using the spin-fermion model, where charged quasiparticles of the copper-oxygen planes are coupled to spin fluctuations. First, we analyzed structures of the…

Employing the elemental sensitivity of x-ray absorption spectroscopy (XAS) and x-ray magnetic circular dichroism (XMCD), we study the valence and magnetic order in the heavy fermion superconductor CeCoIn$_5$. We probe spin population of the…

We have performed powder inelastic neutron scattering measurements on the unconventional superconductor $\beta$-FeSe ($T_{\rm c} \simeq 8\,\mathrm{K}$). The spectra reveal highly dispersive paramagnetic fluctuations emerging from the…

Superconductivity in FeSe emerges from a nematic phase that breaks four-fold rotational symmetry in the iron plane. This phase may arise from orbital ordering, spin fluctuations, or hidden magnetic quadrupolar order. Here we use inelastic…

We use inelastic neutron scattering to study magnetic excitations of the FeAs-based superconductor BaFe$_{1.9}$Ni$_{0.1}$As$_2$ above and below its superconducting transition temperature $T_c=20$ K. In addition to gradually open a spin gap…

Recently, Rourke et al. reported point-contact spectroscopy results on the heavy-fermion superconductor CeCoIn$_5$ [1]. They obtained conductance spectra on the c-axis surfaces of CeCoIn$_5$ single crystals. Their major claims are two-fold:…

We use neutron scattering to study the electron-doped superconducting NaFe$_{0.985}$Co$_{0.015}$As ($T_c=14$ K), which has co-existing static antiferromagnetic (AF) order ($T_N=31$ K) and exhibits two neutron spin resonances ($E_{r1}\approx…

We report $^{115}$In nuclear quadrupolar resonance (NQR) measurements on the heavy-fermion superconductor PuCoIn$_5$, in the temperature range $0.29{\rm K}\leq T\leq 75{\rm K}$. The NQR parameters for the two crystallographically…

I present a brief overview on the interplay between magnetism and superconductivity in one of the Fe-based superconductor systems, \fts, where the research of our group has centered. The parent compound Fe$_{1+y}$Te is an antiferromagnet;…