We investigate spatiotemporal periodic patterns in harmonically trapped Bose–Einstein condensates(BECs)driven by a periodic modulation of the interaction.Resonant with the breathing mode,we show the emergence of a sq...We investigate spatiotemporal periodic patterns in harmonically trapped Bose–Einstein condensates(BECs)driven by a periodic modulation of the interaction.Resonant with the breathing mode,we show the emergence of a square lattice pattern containing two orthonormal stripes.We study the time evolutions of the lattice patterns for different driving strengths and dissipations.We find that its spatial periodicity and temporal oscillating frequency match the Bogoliubov dispersion,which is the intrinsic property of the system and relevant to the parametric amplification of elementary excitations.In the circumstances of strong driving strength and low dissipation,we further observe the triad interaction and the resulting superlattice state,which are well explained by the nonlinear amplitude equation for superimposed stripes.These results shed light on unexplored nonlinear spatiotemporal dynamics of two-dimensional patterns in harmonically trapped BECs that can pave the way for engineering exotic patterns by state-of-the-art experiments.展开更多
Conventional periodic structures usually have nontunable refractive indices and thus lead to immutable photonic bandgaps. A periodic structure created in an ultracold atoms ensemble by externally controlled light can ...Conventional periodic structures usually have nontunable refractive indices and thus lead to immutable photonic bandgaps. A periodic structure created in an ultracold atoms ensemble by externally controlled light can overcome this disadvantage and enable lots of promising applications. Here, two novel types of optically induced square lattices, i.e., the amplitude and phase lattices, are proposed in an ultracold atoms ensemble by interfering four ordinary plane waves under different parameter conditions. We demonstrate that in the far-field regime, the atomic amplitude lattice with high transmissivity behaves similarly to an ideal pure sinusoidal amplitude lattice, whereas the atomic phase lattices capable of producing phase excursion across a weak probe beam along with high transmissivity remains equally ideal. Moreover, we identify that the quality of Talbot imaging about a phase lattice is greatly improved when compared with an amplitude lattice. Such an atomic lattice could find applications in alloptical switching at the few photons level and paves the way for imaging ultracold atoms or molecules both in the near-field and in the far-field with a nondestructive and lensless approach.展开更多
基金supported by the National Natural Science Foundation of China(NSFC)under Grant Nos.12074343(WW and HJL)the Natural Science Foundation of Zhejiang Province of China under Grant No.LZ22A050002(HJL)。
文摘We investigate spatiotemporal periodic patterns in harmonically trapped Bose–Einstein condensates(BECs)driven by a periodic modulation of the interaction.Resonant with the breathing mode,we show the emergence of a square lattice pattern containing two orthonormal stripes.We study the time evolutions of the lattice patterns for different driving strengths and dissipations.We find that its spatial periodicity and temporal oscillating frequency match the Bogoliubov dispersion,which is the intrinsic property of the system and relevant to the parametric amplification of elementary excitations.In the circumstances of strong driving strength and low dissipation,we further observe the triad interaction and the resulting superlattice state,which are well explained by the nonlinear amplitude equation for superimposed stripes.These results shed light on unexplored nonlinear spatiotemporal dynamics of two-dimensional patterns in harmonically trapped BECs that can pave the way for engineering exotic patterns by state-of-the-art experiments.
基金National Natural Science Foundation of China(NSFC)(61605155,61627812)Fundamental Research Funds for the Central Universities
文摘Conventional periodic structures usually have nontunable refractive indices and thus lead to immutable photonic bandgaps. A periodic structure created in an ultracold atoms ensemble by externally controlled light can overcome this disadvantage and enable lots of promising applications. Here, two novel types of optically induced square lattices, i.e., the amplitude and phase lattices, are proposed in an ultracold atoms ensemble by interfering four ordinary plane waves under different parameter conditions. We demonstrate that in the far-field regime, the atomic amplitude lattice with high transmissivity behaves similarly to an ideal pure sinusoidal amplitude lattice, whereas the atomic phase lattices capable of producing phase excursion across a weak probe beam along with high transmissivity remains equally ideal. Moreover, we identify that the quality of Talbot imaging about a phase lattice is greatly improved when compared with an amplitude lattice. Such an atomic lattice could find applications in alloptical switching at the few photons level and paves the way for imaging ultracold atoms or molecules both in the near-field and in the far-field with a nondestructive and lensless approach.
