Dynamic structure factor of two-dimensional Fermi superfluid with Rashba spin-orbit coupling
Year: 2023
Type: article
Abstract: We theoretically calculate the dynamic structure factor of a two-dimensional Rashba-type spin-orbit-coupled (SOC) Fermi superfluid with the random phase approximation and analyze the main characters of dynamical excitation shown by both density and spin dynamic structure factors during a continuous phase transition between a Bardeen-Cooper-Schrieffer superfluid and a topological superfluid. Generally we find three different excitations, including collective phonon excitation, two-atom molecular and atomic excitations, and pair-breaking excitations due to the two-branch structure of the quasiparticle spectrum. It should be emphasized that collective phonon excitation is overlapped with a gapless $DD$-type pair-breaking excitation at the critical Zeeman field ${h}_{c}$ and is imparted a finite width to phonon peak when the transferred momentum $\mathit{q}$ is around the Fermi vector ${k}_{F}$. At a much larger transferred momentum $(\mathit{q}=4{k}_{F})$, the pair-breaking excitation happens earlier than two-atom molecular excitation, which is different from the conventional Fermi superfluid without the SOC effect.
Source: Physical Review A
Authors: Huaisong Zhao, Xu Yan, Shi-Guo Peng, Peng Zou
Language: English
Subfield: Atomic and Molecular Physics, and Optics
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: green
OpenAlex ID: W4386562070