Oscillatory stability of quantum droplets in -symmetric optical lattice

Abstract

We study stability and collisions of quantum droplets (QDs) forming in a binary bosonic condensate trapped in parity-time ()-symmetric optical lattices. It is found that the stability of QDs in the -symmetric system depends strongly on the values of the imaginary part W 0 of the -symmetric optical lattices, self-repulsion strength g, and the condensate norm N. As expected, the -symmetric QDs are entirely unstable in the broken -symmetric phase. However, the -symmetric QDs exhibit oscillatory stability with the increase of N and g in the unbroken -symmetric phase. Finally, collisions between -symmetric QDs are considered. The collisions of droplets with unequal norms are completely different from that in free space. Besides, a stable -symmetric QDs collides with an unstable ones tend to merge into breathers after the collision.