Dark-Soliton Molecules in an Exciton-Polariton Superfluid
Maître, Anne and Lerario, Giovanni and Medeiros, Adria and Claude, Ferdinand and Glorieux, Quentin and Giacobino, Elisabeth and Pigeon, Simon and Bramati, Alberto

Phys. Rev. X 10, 041028 (2020)

Phys. Rev. X 10, 041028  (2020)

The general theory of dark solitons relies on repulsive interactions and, therefore, predicts the impossibility to form dark-soliton bound states. One important exception to this prediction is the observation of bound solitons in nonlocal nonlinear media. Here, we report that exciton-polariton superfluids can also sustain dark-soliton molecules, although the interactions are fully local. With a novel all-optical technique, we create two dark solitons that bind together to form an unconventional dark-soliton molecule. We demonstrate that the stability of this structure and the separation distance between two dark solitons is tightly connected to the driven-dissipative nature of the polariton fluid.