We theoretically investigate the Higgs oscillation in a one-dimensional Raman-type spin–orbit-coupled Fermi superfluid with the time-dependent Bogoliubov–de Gennes equations.By linearly ramping or abruptly changing ...We theoretically investigate the Higgs oscillation in a one-dimensional Raman-type spin–orbit-coupled Fermi superfluid with the time-dependent Bogoliubov–de Gennes equations.By linearly ramping or abruptly changing the effective Zeeman field in both the Bardeen–Cooper–Schrieffer state and the topological superfluid state,we find the amplitude of the order parameter exhibits an oscillating behaviour over time with two different frequencies(i.e.,two Higgs oscillations)in contrast to the single one in a conventional Fermi superfluid.The observed period of oscillations has a great agreement with the one calculated using the previous prediction[Volkov and Kogan,J.Exp.Theor.Phys.38,1018(1974)],where the oscillating periods are now determined by the minimums of two quasi-particle spectrum in this system.We further verify the existence of two Higgs oscillations using a periodic ramp strategy with theoretically calculated driving frequency.Our predictions would be useful for further theoretical and experimental studies of these Higgs oscillations in spin–orbit-coupled systems.展开更多
基金This research was supported by the National Natural Science Foundation of China,Grant No.11804177(P.Z.)the Science Foundation of Zhejiang SciTech University(ZSTU)No.21062339-Y and China Postdoctoral Science Foundation No.2020M680495(X.L.C.).
文摘We theoretically investigate the Higgs oscillation in a one-dimensional Raman-type spin–orbit-coupled Fermi superfluid with the time-dependent Bogoliubov–de Gennes equations.By linearly ramping or abruptly changing the effective Zeeman field in both the Bardeen–Cooper–Schrieffer state and the topological superfluid state,we find the amplitude of the order parameter exhibits an oscillating behaviour over time with two different frequencies(i.e.,two Higgs oscillations)in contrast to the single one in a conventional Fermi superfluid.The observed period of oscillations has a great agreement with the one calculated using the previous prediction[Volkov and Kogan,J.Exp.Theor.Phys.38,1018(1974)],where the oscillating periods are now determined by the minimums of two quasi-particle spectrum in this system.We further verify the existence of two Higgs oscillations using a periodic ramp strategy with theoretically calculated driving frequency.Our predictions would be useful for further theoretical and experimental studies of these Higgs oscillations in spin–orbit-coupled systems.
