We theoretically calculate the dynamic structure factor of two-dimensional
Rashba-type spinorbit coupled (SOC) Fermi superfluid with random phase
approximation, and analyse the main characters of dynamical excitation sh own
by both density and spin dynamic structure factor during a continuous phase
transition between Bardeen-Cooper-Schrieffer superfluid and topological
superfluid. Generally we find three different excitations, including collective
phonon excitation, two-atom molecular and atomic excitations, and pair-breaking
excitations due to two-branch structure of quasi-particle spectrum. It should
be emphasized that collective phonon excitation is overlapped with a gapless DD
type pair-breaking excitation at the critical Zeeman field hc, and is imparted
a finite width to phonon peak when transferred momentum q is around Fermi
vector kF. At a much larger transferred momentum (q = 4kF ), the pair-breaking
excitation happens earlier than two-atom molecular excitation, which is
different from the conventional Fermi superfluid without SOC effect.Comment: 10 pages, 8 figures. arXiv admin note: text overlap with
arXiv:2210.1040