Temperature dependence of the resonance and low-energy spin excitations in superconducting FeTe0.6Se0.4
- University of Tennessee, Knoxville (UTK)
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics
- ORNL
We use inelastic neutron scattering to study the temperature dependence of the low-energy spin excitations in single crystals of superconducting FeTe{sub 0.6}Se{sub 0.4} (T{sub c} = 14 K). In the low-temperature superconducting state, the imaginary part of the dynamic susceptibility at the electron and hole Fermi-surfaces nesting wave vector Q = (0.5, 0.5), {chi}{sup ''} (Q, {omega}), has a small spin gap, a two-dimensional neutron spin resonance above the spin gap, and increases linearly with increasing {h_bar}{omega} for energies above the resonance. While the intensity of the resonance decreases like an order parameter with increasing temperature and disappears at temperature slightly above T{sub c}, the energy of the mode is weakly temperature dependent and vanishes concurrently above T{sub c}. This suggests that in spite of its similarities with the resonance in electron-doped superconducting BaFe{sub 2-x} (Co, Ni){sub x}As{sub 2}, the mode in FeTe{sub 0.6}Se{sub 0.4} is not directly associated with the superconducting electronic gap.
- Research Organization:
- Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). High Flux Isotope Reactor (HFIR)
- Sponsoring Organization:
- USDOE Office of Science (SC)
- DOE Contract Number:
- DE-AC05-00OR22725
- OSTI ID:
- 1041438
- Journal Information:
- Physical Review. B, Condensed Matter and Materials Physics, Vol. 85, Issue 5; ISSN 1098-0121
- Country of Publication:
- United States
- Language:
- English
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