Strong $(\pi ,0)$ spin fluctuations in $\beta$-FeSe observed by neutron spectroscopy

M. C. Rahn, R. A. Ewings, S. J. Sedlmaier +2

We have performed powder inelastic neutron scattering measurements on the unconventional superconductor $\beta$-FeSe ($T_{\mathrm{c}}\simeq 8\mathrm{K}$). The spectra reveal highly dispe…