Vector gap solitons of a binary Bose–Einstein condensate in honeycomb optical lattice

We investigate the formation and dynamic stabilities of vector gap solitons in a binary Bose–Einstein condensate (BEC) loaded in a honeycomb optical lattice. The existence of vector gap solitons is sensitive to the properties of intraspecies and interspecies atomic interactions. We numerically obtain the phase diagram for observing vector gap solitons on the parameter plane of intraspecies and interspecies atomic interactions. Particularly, it is found that the two components of vector gap solitons are always miscible with each other regardless of whether the intraspecies or the interspecies atomic interaction is dominant. We further verify the dynamic stabilities of these vector gap solitons, which depend on the location of soliton in the bandgap. These results have potential application to investigations of localized structures in nonlinear optics.