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.
| Original language | English |
|---|---|
| Article number | 140504 |
| Journal | Physical Review B |
| Volume | 101 |
| Issue number | 14 |
| DOIs | |
| State | Published - Apr 1 2020 |
Funding
We would like to thank R. Feyerherm from HZB Berlin for setting up and operating the dilution refrigerator. Neutron scattering work at Rice is supported by the U.S. Department of Energy, BES under Grant No. DE-SC0012311 (P.D.). The single-crystal synthesis work at Rice is supported by Robert A. Welch Foundation Grant No. C-1839 (P.D.). Sample preparation at Johns Hopkins University is supported by the U.S. Department of Energy Grant No. DE-SC0019331. The access to MACS was provided by the Center for High Resolution Neutron Scattering, a partnership between the National Institute of Standards and Technology and the National Science Foundation under agreement No. DMR-1508249.