Chen, T.; Chen, Y.; Tam, D.W.; Gao, B.; Qiu, Y.; Schneidewind, A.; Radelytskyi, I.; Prokes, K.; Chi, S.; Matsuda, M.; Broholm, C.; Dai, P.: Anisotropic effect of a magnetic field on the neutron spin resonance in FeSe. Physical Review B 101 (2020), p. 140504(R)/1-7
10.1103/physrevb.101.140504
Open Access Version
Abstract:
We use inelastic neutron scattering to study the effect of a magnetic field on the neutron spin resonance (Er=3.6 meV) of superconducting FeSe (Tc=9 K). While a field aligned along the in-plane direction broadens and suppresses the resonance, a c-axis aligned field does so much more efficiently, consistent with the anisotropic field-induced suppression of the superfluid density from the heat capacity measurements. These results suggest that the resonance in FeSe is associated with the superconducting electrons arising from orbital selective quasiparticle excitations between the hole and electron Fermi surfaces.