Long-range interactions of double beams in party-time symmetric lattices in the presence of nonlocal nonlinearities

The co-propagation of double beams in party-time symmetric lattices in the presence of nonlocal nonlinearities has been investigated. An interesting phenomenon has been found that the energy of the beam in the right side has increased almost monotonously, while it oscillates in the absence of nonlinearities. The energy increase can be controlled by adjusting the incident angle of the beam in the left side, since light propagating in party-time symmetric arrays can distinguish left from right. This findings pave the way to all-optical controls in the nonlinear regime.