Inelastic-neutron-scattering measurements were performed on a single crystal of the heavy-
fermion paramagnet U Te 2 above its superconducting temperature. We confirm the …

Superconductivity (SC) and ferromagnetism (FM) are normally antagonistic, and their
coexistence in a single crystalline material appears to be very rare. Over a decade ago, the …

In the local or itinerant extreme, magnetic excitations can be described by the Heisenberg
model which treats electron spins as localized moments, or by the itinerant-electron model …

The neutron spin resonance is generally regarded as a key to understanding the
magnetically mediated Cooper pairing in unconventional superconductors. Here, we report …

Magnetic excitations and magnetic structure of EuRbFe 4 As 4 were investigated by inelastic
neutron scattering (INS), neutron diffraction, and random phase approximation (RPA) …

Here we report the investigation on correlation between the transport properties and the
corresponding stability of the lattice structure for CaK (Fe 1− x Ni x) 4 As 4 (x= 0.04 and 0), a …

Spin-orbit coupling (SOC) is a key to understand the magnetically driven superconductivity
in iron-based superconductors, where both local and itinerant electrons are present and the …

We use ultrafast optical spectroscopy to study the nonequilibrium quasiparticle relaxation
dynamics of the iron-based superconductor KCa2Fe4As4F2 with T c= 33.5 K. Our results …

Honeycomb and kagome lattices can host propagating excitations with non-trivial topology
as defined by their evolution along closed paths in momentum space. Excitations on such …

FeSe 1− x S x superconductors are commonly considered layered van der Waals materials
with negligible interlayer coupling. Here, using inelastic neutron scattering to study spin …