  Inelastic neutron scattering measurements of CaFe2As2 under applied
hydrostatic pressure show that the antiferromagnetic spin fluctuations observed
in the ambient pressure, paramagnetic, tetragonal (T) phase are strongly
suppressed, if not absent, in the collapsed tetragonal (cT) phase. These
results are consistent with a quenched Fe moment in the cT phase and the strong
decrease in resistivity observed upon crossing the boundary from the T to cT
phase. The suppression or absence of static antiferromagnetic order and dynamic
spin fluctuations in the non-superconducting cT phase supports the notion of a
coupling between spin fluctuations and superconductivity in the iron arsenides.
