arXiv subjects

Rishabh Kaurav

Publications and source records attributed to Rishabh Kaurav.

3 recordsLinked to original sources

arXiv2026

Generative modelling powered by room-temperature polariton condensates

Generative modelling requires efficient stochastic nonlinear transformations and physical platforms that can naturally realise them. We experimentally demonstrate that nonlinear optical systems operating in the strong light-matter coupling regime can serve as physical transformation layers for conditional generative modelling. Specifically, we develop a workflow in which room-temperature exciton-polariton condensates formed in organic dye microcavities act as a physical stochastic transform within a generative adversarial network and enable conditional digit-to-image translation. By using the nonlinear many-body dynamics and intrinsic stochasticity of polariton condensates, the workflow outperforms baseline approaches based on digitally injected perturbations. We find that polariton-enabled sampling via generative adversarial network (Polariton GAN) yields improved inception score, digit preservation accuracy and structural similarity compared with both digital sampling and laser-based systems. We further show that spatially correlated output variations can naturally regularise adversarial training and enhance output diversity. Our results establish polariton condensation as a new computational resource for generative modelling, opening a pathway towards physics-enhanced machine learning systems.

cond-mat.dis-nn↗

arXiv2025

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.

physics.optics↗

arXiv2025

Nonlinear Dynamics in the Formation of Molecular Polariton Condensates

Exciton-polaritons - hybrid light-matter quasiparticles - can undergo Bose-Einstein-like condensation at elevated temperatures owing to their lower effective mass. This becomes even more pronounced in the context of molecular polariton condensates where the large exciton binding energy of Frenkel excitons facilitates condensation at room temperature. While widely studied as low-threshold coherent light sources, the dynamics of their condensation remain poorly understood, partly due to the limitations of existing kinetic models. Here, we use excitation correlation photoluminescence (ECPL), a nonlinear optical technique with 220fs resolution, to probe molecular polariton condensation in Rhodamine-B-doped small-molecule ionic isolation lattices (SMILES). This platform promotes dipole alignment and suppresses detrimental intermolecular interactions. ECPL reveals condensate formation within hundreds of femtoseconds, driven by radiative scattering from the reservoir. A sustained population beyond the polariton lifetime suggests an additional feeding mechanism from higher momentum states in the lower polariton dispersion. These results provide quantitative insight into condensation timescales and mechanisms, advancing our control over polariton dynamics.

cond-mat.mtrl-sci↗