23 datasets found

The recently discovered iron based superconductors have transition temperatures second only to the cuprates. The majority of these compounds display superconductivity after...

Understanding the magnetic exchange coupling and fundamental Hamiltonian of the parent compound of FeAs-based superconductors is extremely important, because such information...

One fundamental issue in the iron-based superconductors is whether the conventional local moment Heisenberg model is sufficient to describe magnetism in these materials, or...

Superconductivity (SC) in unconventional superconductors is believed to be related to magnetism. However, in AyFe1.6+xSe2 (A = K, Rb, Cs) system discovered in late 2010, the SC...

The debate whether interband or intraband scattering is crucial for Fe-based superconductors is not settled down yet. Investigation a system with completely missing electron...

Spin excitations is correlated with superconductivity in high Tc superconductors. The spin excitations in La2-xSrxCuO4 superconductors become weaker in overdoped region and...

Neutron spin resonance mode is a common feature in different classes of magnetic superconductors; nonetheless, the microscopic origin of the mode is still unclear. In general,...

The spin excitations in superconducting LiFeAs have been found evolved from incommensurate peaks to commensurate peak at low energy. But the spin resonance is still not clear in...

Recent unpublished data collected at MAPS by our group revealed that the spin wave dispersion of the Ba(122) parent differ significantly from Ca(122). In Ba(122) there is a...

The recent discovered iron pnictide superconductor which shows a transition temperature up to 50K has drawn much attention in the community. There are indications that...

The newly discovered AxFe2-ySe2 (A=K,Rb,Cs) compounds have attracted great interests because of their parent compounds are insulators instead of being metallic [2-6]....

We clearly observed incommensurate (IC) magnetic excitation in KFe2As2 above Tc with Ei=80 mev on ARCS at ORNL. Though we got beam time at LET, we wish to see how the IC changes...

Though NaFeAs shares the same crystallographic structure with LiFeAs, there are many different aspects between them. We would like to compare the magnetic excitation in it with...

We propose to study the spin wave excitations of nonsuperconducting single crystal Pr0.88LaCe0.12CuO4 (PLCCO). Previous experiments on superconducting PLCCO have shown that spin...

The alkaline iron selenide RbFe1.6+xSe2 superconductors are a new system of iron-based superconductor with Tc up to 32K. According to recent experimental results, the...

Neutron spin resonance mode is a common feature in different classes of magnetic superconductors; nonetheless, the microscopic origin of the mode is still unclear. In general,...

There has been much research into the recently discovered iron based superconductors, but so far only the magnetic excitations at low energy have been investigated. We propose...

From our previous data on BaFe2As2 and BaFe1.9Ni0.1As2, one may assume that the superconductivity only affects the low energy excitations. But for Ba0.67K0.33Fe2As2, the doping...

We propose muSR studies on superfluid density in the overdoped La2-xSrxCuO4 (LSCO). The Hayden group (Bristol) has been growing high-quality LSCO single crystals, and performed...

Motivated by the observation of incommensure magnetic order in Ba(Fe1-xCox)2As2, we have recently grown BaFe2-xNixAs2 crystals with systematic electron doping level especially...