Related papers: High energy spin excitations in BaFe2As2
Inelastic neutron scattering measurements of paramagnetic SrCo$_{2}$As$_{2}$ at T=5 K reveal antiferromagnetic (AFM) spin fluctuations that are peaked at a wavevector of $\textbf{Q}_{\mathrm{AFM}}=(1/2,1/2,1)$ and possess a large energy…
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…
We theoretically examine the orbital excitations coupled to the spin degree of freedom in the parent state of the iron-arsenide superconductor, based on the calculation in a five-band itinerant model. The calculated Fe $L_3$-edge resonant…
The magnetic properties in the parent compounds are often intimately related to the microscopic mechanism of superconductivity. Here we report the first direct measurements on the electronic structure of a parent compound of the newly…
Magnetic inelastic neutron scattering (INS) studies of iron-based superconductors reveal a strongly temperature-dependent spin-fluctuation spectrum in the normal conducting state, which develops a prominent low-energy resonance feature when…
Raman scattering spectra of new Fe-based S=2 spin ladder compound BaFe$_2$Se$_2$O are measured in a temperature range between 15 K and 623 K. All six A$_{1g}$ and two B$_{1g}$ Raman active modes of BaFe$_2$Se$_2$O, predicted by the…
We performed inelastic neutron scattering on powder sample of the P-doped iron-based superconductor BaFe2(As0.65P0.35)2 with Tc = 30K, whose superconducting (SC) order parameter is expected to have line nodes. We have observed spin…
We report a high-pressure 75As NMR study on the heavily hole-doped iron pnictide superconductor KFe2As2 (Tc~3.8 K). The low-energy spin fluctuations are found to decrease with applied pressure up to 2 GPa, but then increase again, changing…
Antiferromagnetic spin fluctuations were investigated in the normal states of the parent ($x = 0$), under-doped ($x = 0.04$) and optimally-doped ($x = 0.06$) Ba(Fe$_{1-x}$Co$_x$)$_2$As$_2$ single crystals using inelastic neutron scattering…
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…
We report neutron scattering measurements of the spectrum of magnetic excitations in the stripe-ordered phase of La2-xSrxNiO4 (x=0.275 and 1/3). The propagating spin excitations follow a similar dispersion relation for the two compositions,…
We use inelastic neutron scattering to study energy and wave vector dependence of spin fluctuations in SrCo$_2$As$_2$, derived from SrFe$_{2-x}$Co$_x$As$_2$ iron pnictide superconductors. Our data reveals the coexistence of…
We use inelastic neutron scattering to study the temperature and energy dependence of the spin excitation anisotropy in uniaxial-strained electron-doped iron pnictide BaFe$_{1.9}$Ni$_{0.1}$As$_2$ near optimal superconductivity ($T_c=20$ K).…
We present inelastic neutron scattering measurements of the antiferromagnetic insulator CaMn$_2$Sb$_2$, which consists of corrugated honeycomb layers of Mn. The dispersion of magnetic excitations has been measured along the H and L…
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…
The NMR results in iron pnictides BaFe2(As1-xPx)2 and Ba(Fe1-xCox)2As2 are analyzed based on the self-consistent renormalization (SCR) spin fluctuation theory. The temperature dependence of the NMR relaxation rate (T_1)^{-1} as well as the…
The spin fluctuation spectra from nonsuperconducting Cu-substituted, and superconducting Co-substituted, BaFe2As2 are compared quantitatively by inelastic neutron scattering measurements and are found to be indis- tinguishable. Whereas…
Spin excitations stemming from the metallic phase of the ferrochalcogenide superconductor K(0.77)Fe(1.85)Se(2) (T_c=32 K) were mapped out in the ab plane by means of the time-of-flight neutron spectroscopy. We observed a magnetic resonant…
Magnetic correlations near the magneto-structural phase transition in the bilayer iron pnictide parent compound, BaFe$_2$As$_2$, are measured. In close proximity to the antiferromagnetic phase transition in BaFe$_2$As$_2$, a crossover to…
We report neutron scattering measurements of single-crystalline YFe$_2$Ge$_2$ in the normal state, which has the same crystal structure to the 122 family of iron pnictide superconductors. YFe$_2$Ge$_2$ does not exhibit long range magnetic…