Abstract
We use inelastic neutron scattering to study the effect of an in-plane magnetic field on the magnetic resonance in optimally doped superconductors FeSeTe ( K) and BaFeNiAs ( K). While the magnetic field up to 14.5 T does not change the energy of the resonance, it partially suppresses and the corresponding superconductivity-induced intensity gain of the mode. However, we find no direct evidence for the field-induced spin-1 Zeeman splitting of the resonance. Therefore it is still unclear if the resonance is the long-sought singlet-triplet excitation directly coupled to the superconducting electron Cooper pairs.
- Received 15 March 2011
DOI:https://doi.org/10.1103/PhysRevB.84.024518
©2011 American Physical Society