We investigate how three-body interactions affect the elementary excitations and dynamic structure factor of a Bose- Einstein condensate trapped in a one-dimensional optical lattice. To this end, we numerically solve ...We investigate how three-body interactions affect the elementary excitations and dynamic structure factor of a Bose- Einstein condensate trapped in a one-dimensional optical lattice. To this end, we numerically solve the Gross-Pitaevskii equation and then the corresponding Bogoliubov equations. Our results show that three-body interactions can change both the Bogoliubov band structure and the dynamical structure factor dramatically, especially in the case of the two-body interaction being relatively small. Furthermore, when the optical lattice is strong enough, the analytical results, combined with the sum-rule approach, help us to understand that： the effects of three-body interactions on the static structure Ihctor can be significantly amplified by an optical lattice. Our predictions should be observable within the current Bragg spectroscopy experiment.展开更多
We study modulational instability of a resonantly polariton condensate in a discrete lattice.Employing a discrete gain-saturation model,we derive the dispersion relation for the modulational instability by means of th...We study modulational instability of a resonantly polariton condensate in a discrete lattice.Employing a discrete gain-saturation model,we derive the dispersion relation for the modulational instability by means of the linear-stability analysis.Effects of the pumping strength,the nonlinearity,the strength of the detuning,and the coupling strength on the modulation instability are investigated.It is found that the interplay between these parameters will dramatically change the modulational instability condition.We believe that the predicted results in this work can be useful for future possible experiment of exciton-polariton condensate in lattices.展开更多
Considering the non-locality of interactions in a Bose–Einstein condensate, the existence and stability of solitons subject to a PT-symmetric potential are discussed. In the framework of the variational approach, we ...Considering the non-locality of interactions in a Bose–Einstein condensate, the existence and stability of solitons subject to a PT-symmetric potential are discussed. In the framework of the variational approach, we investigate how the non-locality of interactions affects the self-localization and stability of a condensate with attractive two-body interactions. The results reveal that the non-locality of interactions dramatically influences the shape,width, and chemical potential of the condensate. Analytically variational computation also predicts that there exists a critical negative non-local interaction strength(p_c < 0) with each fixed two-body interaction(g_0 < 0),and there exists no bright soliton solution for p_0 < p_c. Furthermore, we study the effect of the non-locality interactions on the stability of the solitons using the Vakhitov–Kolokolov stability criterion. It is shown that for a positive non-local interaction(p_0 > 0), there always exist stable bright solitons in some appropriate parameter regimes.展开更多
基金supported by the National Natural Science Foundation of China (Grant Nos. 11004200 and 11274315)
文摘We investigate how three-body interactions affect the elementary excitations and dynamic structure factor of a Bose- Einstein condensate trapped in a one-dimensional optical lattice. To this end, we numerically solve the Gross-Pitaevskii equation and then the corresponding Bogoliubov equations. Our results show that three-body interactions can change both the Bogoliubov band structure and the dynamical structure factor dramatically, especially in the case of the two-body interaction being relatively small. Furthermore, when the optical lattice is strong enough, the analytical results, combined with the sum-rule approach, help us to understand that： the effects of three-body interactions on the static structure Ihctor can be significantly amplified by an optical lattice. Our predictions should be observable within the current Bragg spectroscopy experiment.
基金the National Natural Science Foundation of China(Grant No.11805116)the Natural Science Basic Research Plan in Shaanxi Province,China(Grant No.2023-JC-YB-037).
文摘We study modulational instability of a resonantly polariton condensate in a discrete lattice.Employing a discrete gain-saturation model,we derive the dispersion relation for the modulational instability by means of the linear-stability analysis.Effects of the pumping strength,the nonlinearity,the strength of the detuning,and the coupling strength on the modulation instability are investigated.It is found that the interplay between these parameters will dramatically change the modulational instability condition.We believe that the predicted results in this work can be useful for future possible experiment of exciton-polariton condensate in lattices.
基金the National Natural Science Foundation of China under Grant Nos 11647017,11805116 and 21703166the Science Research Fund of Shaanxi University of Science and Technology under Grant No BJ16-03
文摘Considering the non-locality of interactions in a Bose–Einstein condensate, the existence and stability of solitons subject to a PT-symmetric potential are discussed. In the framework of the variational approach, we investigate how the non-locality of interactions affects the self-localization and stability of a condensate with attractive two-body interactions. The results reveal that the non-locality of interactions dramatically influences the shape,width, and chemical potential of the condensate. Analytically variational computation also predicts that there exists a critical negative non-local interaction strength(p_c < 0) with each fixed two-body interaction(g_0 < 0),and there exists no bright soliton solution for p_0 < p_c. Furthermore, we study the effect of the non-locality interactions on the stability of the solitons using the Vakhitov–Kolokolov stability criterion. It is shown that for a positive non-local interaction(p_0 > 0), there always exist stable bright solitons in some appropriate parameter regimes.
