自旋张量-动量耦合作用下自旋1玻色-爱因斯坦凝聚体的调制不稳定性.

The modulation instabilities of continuous-wave states in spin-1 Bose-Einstein condensates under spin tensor-momentum couplings are investigated. With the help of the dispersion relation between perturbation frequency and wavenumber, we find that the modulation instability of the system can be adequately described by six unequal branches. Further analysis shows that, for a given Raman coupling strength and atom-atom interaction strength, the modulation instability growth rate distribution in momentum space is symmetric about k=0 and can be characterized by several different instability bands. We also calculate the growth rate of modulation instability in spin-orbit coupled spin-1 Bose-Einstein condensates under the same parameter conditions and compare with the former results. Besides the different number of bands and band intensities, the modulation instability of Bose-Einstein condensates with spin-orbit coupling is actually only related to three unequal branches, which stem from its different symmetries of the single-particle Hamiltonian of a spin-tensor-momentum coupled BEC system. These results not only contribute to the understanding of the nonlinear dynamic properties of the ground state, but also to the analysis of possible nonlinear excitations in the system. [ABSTRACT FROM AUTHOR]