Related papers: Testing the itinerancy of spin dynamics in superco…
Mechanism of unconventional superconductivity in FeSe has been intensely scrutinized recently because of a variety of exotic properties unprecedented for other iron-based superconductors. A central unanswered question concerns the origin of…
Inelastic neutron scattering is used to study transverse-polarized magnetic excitations in the quasi-one-dimensional S=1/2 antiferromagnet BaCu_2Si_2O_7, where the saturation value for the N\'eel order parameter is $m_0=0.12 \mu_{\rm B}$…
Spin caloritronics studies the interplay between charge-, heat- and spin-currents, which are initiated by temperature gradients in magnetic nanostructures. A plethora of new phenomena has been discovered that promises, e.g., to make wasted…
Inelastic neutron scattering has been used to measure the low-energy spin excitations in the ordered charge-stripe phase of La(2)NiO(4+d) with d=0.133. Spin-wave-like excitations disperse away from the incommensurate magnetic superlattice…
Arguably the most intriguing aspect of the physics of cuprates is the close proximity between the record high-Tc superconductivity (HTSC) and the antiferromagnetic charge-transfer insulating state driven by Mott-like electron correlations.…
We report ^{11}B and ^{195}Pt NMR measurements in non-centrosymmetric superconductor Li_2Pt_3B. We find that the spin susceptibility measured by the Knight shift remains unchanged across the superconducting transition temperature T_c. With…
Monolayers of a prototypical cuprate high transition-temperature ($T_C$) superconductor $Bi_2Sr_2CaCu_2O_{8+\delta}$ (Bi2212) was recently found to show $T_C$ and other electronic properties similar to those of the bulk. The robustness of…
Nuclear magnetic resonance (NMR) experiments on single crystals of HgBa$_{2}$CuO$_{4+\delta}$ are presented that identify two distinct temperature-dependent spin susceptibilities: one is due to a spin component that is temperature-dependent…
We have investigated the transition temperature $T_{\rm c}(H)$ of superconductiv ity in quasi-two-dimensional (Q2D) tight-binding electrons in a strong magnetic field. When the magnetic field is parallel to 2D conducting plane, $T_{\rm…
Inelastic neutron scattering is used to probe the collective spin excitations of the near optimally-doped superconductor Ba(Fe1-xCox)2As2 ($x$=0.065). Previous measurements on the antiferromagnetically ordered parents of this material show…
To the Hubbard model on a square lattice we add an interaction, $W$, which depends upon the square of a near-neighbor hopping. We use zero temperature quantum Monte Carlo simulations on lattice sizes up to $16 \times 16$, to show that at…
In view of the recent experimental facts in the iron-pnictides, we make a proposal that the itinerant electrons and local moments are simultaneously present in such multiband materials. We study a minimal model composed of coupled itinerant…
Tunneling measurements have been carried out on heavily underdoped, slightly overdoped and partially Ni-substituted Bi2212 single crystals by using a break-junction technique. We find that in-plane tunneling spectra below Tc are the…
Thermal conductivity measurements have been performed on the superconducting ferromagnet UCoGe down to very low temperature and under magnetic field. In addition to the electronic quasiparticle thermal conductivity, additional contributions…
We use inelastic neutron scattering to study the temperature dependence of the low-energy spin excitations in single crystals of superconducting FeTe$_{0.6}$Se$_{0.4}$ ($T_c=14$ K). In the low-temperature superconducting state, the…
The main purpose of this brief review is to present a sketch of the mechanism of high-Tc superconductivity based mainly on tunneling measurements in cuprates. In the review, we shall mostly discuss tunneling spectroscopy in Bi2212. Analysis…
Magnetic excitations in a weakly coupled spin dimers and chains compound Cu2Fe2Ge4O13 are measured by inelastic neutron scattering. Both structure factors and dispersion of low energy excitations up to 10 meV energy transfer are well…
Polarized and unpolarized neutron triple-axis spectrometry was used to study the dynamical magnetic susceptibility $\chi^{\prime\prime}({\bf q},\omega)$ as a function of energy ($\hbar\omega$) and wave vector (${\bf q}$) in a wide…
The excitations responsible for producing high-temperature superconductivity in the cuprates have not been identified. Two promising candidates are collective spin excitations and phonons. A recent argument against spin excitations has been…
Motivated by recent attention to a potential antiferromagnetic quantum critical point at $x_c\sim 0.19$, we have used inelastic neutron scattering to investigate the low-energy spin excitations in crystals of La$_{2-x}$Sr$_x$CuO$_4$…