Passive Routing of a Quantum Fluid of light

J. Beierlein; E. Rozas et ál..

Physical Review Letters 126, 075302 (Feb 2021)

In this work, the passive routing of a propagating quantum fluid of light is demonstrated. This routing is achieved by using a Josephson-like oscillation of the fluid between two coupled waveguides. Hybrid light-matter particles, called exciton-polaritons, can undergo a phase transition into a bosonic condensed state. This state exhibits exceptional effects, e.g., pronounced nonlinearities, quantized vortices or superfluidity, thus justifying the designation “Quantum Fluid of Light”. We have successfully routed such a fluid, carrying out a precise control of the coupling between two confining waveguides, paving the way towards the development of full-optical, polaritonic logic networks. The partition of the condensate between the two arms of the couplers can be conveniently achieved by adjusting the energy and propagation speed inside a single device or the coupling strength in different devices.