In a triclinic iron pnictide superconductor, a spin resonance precursor, Nernst signal, and NMR density-of-states reduction all point to preformed Cooper pairs persisting to T* = 45 K, above Tc = 30 K.
Low-energy spin excitations in Li(0.8)Fe(0.2)ODFeSe superconductor studied with inelastic neutron scattering
1 Pith paper cite this work. Polarity classification is still indexing.
1
Pith paper citing it
abstract
We report an inelastic neutron scattering study of single crystals of (Li$_{0.8}$Fe$_{0.2}$)ODFeSe. Temperature-dependent low-energy spin excitations are observed near $\mathbf{Q}=$ (0.5, 0.27, 0.5) and equivalent wave vectors symmetrically surrounding $\mathbf{Q}=$ (0.5, 0.5, 0.5) in the 1-Fe Brillouin zone, consistent with a Fermi-surface-nesting description. The excitations are broadly distributed in energy, ranging from 16 to 35 meV. Upon cooling below the superconducting critical temperature ($T_\mathrm{c}$), magnetic response below twice the superconducting gap $2\Delta_\mathrm{SC}$ exhibits an abrupt enhancement, consistent with the notion of spin resonance, whereas the response at higher energies increases more gradually with only a weak anomaly at $T_\mathrm{c}$. Our results suggest that (Li$_{0.8}$Fe$_{0.2}$)ODFeSe might be on the verge of a crossover between different Cooper-pairing channels with distinct symmetries.
fields
cond-mat.supr-con 1years
2025 1verdicts
CONDITIONAL 1representative citing papers
citing papers explorer
-
Preformed Cooper Pairs in a Triclinic Iron Pnictide Superconductor
In a triclinic iron pnictide superconductor, a spin resonance precursor, Nernst signal, and NMR density-of-states reduction all point to preformed Cooper pairs persisting to T* = 45 K, above Tc = 30 K.