Nonlinear optical phenomena due to dissipative or nonstationary processes

Herrmann Herrmann, Bernd Wilhelmi

Uwe Langbein, F. Lederer, H. E. Ponath

V. V. Volokhovskii, A. S. Chirkin

Arkadiusz Kosior, Karol Gietka, Farokh Mivehvar +1 more

Driven-dissipative light-matter systems can exhibit collective nonequilibrium phenomena due to loss and gain processes on the one hand and effective photon-photon interactions on the other hand. As a generic example we study a bosonic lattice system implemented via an array of driven-dissipative coupled nonlinear resonators with linearly increasing resonance frequencies across the lattice. The model also describes a driven-dissipative Bose-Hubbard model in a tilted potential without a particle-conservation constraint. We numerically predict a diverse range of stationary and nonstationary states resulting from the interplay of the tilt, tunneling, on-site interactions, and loss and gain processes. Our key finding is that, under weak on-site interactions, the bosons mostly condense into a selected, single-particle Wannier-Stark state without exhibiting the expected Bloch oscillations. As the strength of the on-site interactions increase, a nonstationary regime emerges which, surprisingly, exhibits periodic Bloch-type oscillations. As a direct consequence of the driven-dissipative nature of the system we predict a highly nontrivial phase diagram including regular oscillating as well as chaotic dynamical regimes. While a straightforward photonic implementation using microwave or optical modes is possible, such dynamics might also be observable for an ultracold gas in a vertical lattice with gravity or a tilted external potential.

Uwe Langbein, F. Lederer, H. E. Ponath

Jan Peřina