Strongly fluctuating moments in the high-temperature magnetic superconductor RbEuFe4As4

Fluctuating magnetic moments in liquid metals.

We reanalyze literature data on neutron scattering by liquid metals and show that there is an additional broad (in energy) quasielastic mode present that is absent in x-ray scattering. This mode cannot be accounted for by the standard coherent and incoherent scattering mechanisms. We argue that this mode indicates that nonmagnetic liquid metals possess a magnetic moment which fluctuates on a pi...

CeRu2: A magnetic superconductor with extremely small magnetic moments.

Muon-spin-relaxation experiments and ac low-field magnetization measurements have been carried out on the superconductor CeRu2. The relaxation rate of the muon-spin polarization in zero field exhibits a small but significant increase below TM.40 K, which is suppressed by applying a longitudinal field. This result taken together with magnetization measurements provides definite evidence for the ...

Magnetic-field-enhanced incommensurate magnetic order in the underdoped high-temperature superconductor YBa2Cu3O6.45.

We present a neutron-scattering study of the static and dynamic spin correlations in the underdoped high-temperature superconductor YBa2Cu3O6.45 in magnetic fields up to 15 T. The field strongly enhances static incommensurate magnetic order at low temperatures and induces a spectral-weight shift in the magnetic-excitation spectrum. A reconstruction of the Fermi surface driven by the field-enhan...

Magnetic - Field - Enhanced Incommensurate Magnetic Order in the Underdoped High - Temperature Superconductor YBa

Evolution of the dynamical pairing across the phase diagram of a strongly correlated high-temperature superconductor.

We study the dynamics of the Cooper pairing across the T = 0 phase diagram of the two-dimensional Hubbard model, relevant for high-temperature superconductors, using a cluster extension of dynamical mean-field theory. We find that the superconducting pairing function evolves from an unconventional form in the overdoped region into a more conventional boson-mediated retarded form in the underdop...