Seminarium Fizyki Politechniki Wrocławskiej

Quasi-interacting, Room temperature Organic Exciton-Polariton Condensates in tailored Landscapes

dr Christian Schneider

Technische Physik and Wilhelm Conrad Röntgen-Center for Complex Material Systems, University of Würzburg, Germany

Interacting Bosonic condensates, loaded in periodic potentials have emerged as a prime system for on-chip quantum simulation, exploration of exotic quantum phases, and topological photonics. However, such experiments, which rely on a well-defined shaping of the potential landscape of the condensates, have been restricted to ultra-cold temperatures in atomic systems in laser traps, or cryogenic temperatures for exciton-polaritons in the mature GaAs platform. In our work, we present first experiments conducted on a condensate of exciton-polaritons in a lattice at ambient conditions. We utilize fluorescent proteins as an excitonic gain material, providing ultra-stable Frenkel excitons, and directly take advantage of their soft nature by mechanically shaping them in the photonic lattice environment.

I will discuss the following observations:

• The high quality of our device allows us to generate a close-to ideal bandstructure of the lattice, arranged by tightly bound polaritonic traps.
• The high structural quality of our material allows us to enter the regime of bosonic condensation at ambient condition in this lattice.
• Microscopic modelling allows us to establish the fundamental understanding about polaritonic non-linearities based on Frenkel-Excitons.
• By shaping the pump spot, we can load the condensate into distinct lattice modes and symmetries at will. This capability is a powerful tool for any sort of advanced experiments relying on collective transitions of coherent bosonic states.