Towards coherent polaritonic circuits operating at room temperature
Polariton condensation is a potential system state for performing analog computations, given that it exhibits quantum behavior at macroscopic scales readily probed with low-cost optical methods. Current methods of fabricating devices in polariton microcavities largely involve patterning the devices via e-beam lithography before the cavity is completed, which offers less flexibility in device creation and reduces the maximum possible refractive index contrast. Moreover, the momentum and spatial distributions of the condensate are highly dependent on the host platform, and it has been difficult to preserve the desired behavior when modifying a given cavity. Here we introduce a method that addresses both of these challenges with the creation of polaritonic circuits of arbitrary forms etched via Focused Ion Beam into an organic microcavity based on Rhodamine 3B Perchlorate within a Small Molecule Ionic Isolation Lattices complex. We demonstrate room temperature condensation and propagation of polaritons in rectangular and trapezoidal waveguides by analyzing spatial and angle-resolved photoluminescence. We also discuss the blue-shifting and non-zero momentum of the condensate and show that it is strongly confined up to several higher energy levels. As an example, we report the spatial profiles of condensation in custom devices, such as a ring waveguide, a Y-splitter, and a Mach-Zehnder interferometer. This work represents a first step towards the realization of more complex, fully integrated, coherent polaritonic circuits operating at room temperature.