# Room temperature Organic Exciton-Polariton Condensate in a Lattice

## TL;DR

This paper reports the first demonstration of an organic exciton-polariton condensate in a lattice at room temperature, using fluorescent proteins to enable flexible, cost-effective, and ambient-condition polaritonic systems.

## Contribution

It introduces a novel organic polariton platform operating at room temperature with mechanically shaped lattices, expanding the potential for on-chip quantum simulations and nonlinear phenomena.

## Key findings

- Controlled loading of condensates in different lattice modes
- Observation of gap solitonic modes due to effective interactions
- Validation of organic materials as viable polariton platforms

## Abstract

Interacting Bosons, loaded in artificial lattices, have emerged as a modern platform to explore collective manybody phenomena, quantum phase transitions and exotic phases of matter as well as to enable advanced on chip simulators. Such experiments strongly rely on well-defined shaping the potential landscape of the Bosons, respectively Bosonic quasi-particles, and have been restricted to cryogenic, or even ultra-cold temperatures. On chip, the GaAs-based exciton-polariton platform emerged as a promising system to implement and study bosonic non-linear systems in lattices, yet demanding cryogenic temperatures. In our work, we discuss the first experiment conducted on a polaritonic lattice at ambient conditions: We utilize fluorescent proteins as an excitonic gain material, providing ultra-stable Frenkel excitons. We directly take advantage of their soft nature by mechanically shaping them in the photonic one-dimensional lattice. We demonstrate controlled loading of the condensate in distinct orbital lattice modes of different symmetries, and finally explore, as an illustrative example, the formation of a gap solitonic mode, driven by the interplay of effective interaction and negative effective mass in our lattice. The observed phenomena in our open dissipative system are comprehensively scrutinized by a nonequilibrium model of polariton condensation. We believe, that this work is establishing the organic polariton platform as a serious contender to the well-established GaAs platform for a wide range of applications relying on coherent Bosons in lattices, given its unprecedented flexibility, cost effectiveness and operation temperature.