Partial quantum revivals of localized condensates in distorted lattices

Abstract

We report on a peculiar propagation of bosons loaded by a short Laguerre–Gaussian pulse in a nearly flat band of a lattice potential. Taking a system of exciton polaritons in a kagome lattice as an example, we show that an initially local- ized condensate propagates in a specific direction in space, if anisotropy is taken into account. This propagation consists of quantum jumps, collapses, and revivals of the whole com- pact states, and it persists given any direction of anisotropy. This property reveals its signatures in the tight-binding model, and, surprisingly, it is much more pronounced in a continuous model. Quantum revivals are robust to the repulsive interaction and finite lifetime of the particles. Since no magnetic field or spin–orbit interaction is required, this system provides a new kind of easily implementable optical logic. ©2020 Optical Society of America