Neutron scattering resonance and the iron-pnictide superconducting gap
Neutron scattering resonance and the iron-pnictide superconducting gap
The existence of a neutron scattering resonance at a wave vector ${q}^{\ensuremath{\ast}}$ implies a sign change of the gap between two Fermi-surface regions separated by wave vector ${q}^{\ensuremath{\ast}}$. For the Fe pnictides, a resonance has been observed for a wave vector ${q}^{\ensuremath{\ast}}$ which connects a hole Fermi surface around the …