Polariton condensation in photonic crystals with high molecular orientation

Abstract

We study Frenkel exciton-polariton Bose-Einstein condensation in a two-dimensional defect-free triangular photonic crystal with an organic semiconductor active medium containing bound excitons with dipole moments oriented perpendicular to the layers. We find photonic Bloch modes of the structure and consider their strong coupling regime with the excitonic component. Using the Gross-Pitaevskii equation for exciton polaritons and the Boltzmann equation for the external exciton reservoir, we demonstrate the formation of condensate at the points in reciprocal space where photon group velocity equals zero. Further, we demonstrate condensation at non-zero momentum states for transverse magnetic-polarized photons in the case of a system with incoherent pumping, and show that the condensation threshold varies for different points in the reciprocal space, controlled by detuning.

Tailoring Dispersion of Room-Temperature Exciton-Polaritons with Perovskite-Based Subwavelength Metasurfaces

“…It could be the building block of polariton valleytronic physics. 52,53 Indeed, recent theoretical works have predicted that Bose-Einstein condensation of polaritons with W-shaped dispersion would take place at the valley extrema, 53 thus paving the way to study Josephson oscillation in momentum space, 54 spontaneous symmetry breaking and two-mode squeezing. 52 Moreover, when not working at the extrema but at k x = 0, the W-shaped dispersion is also a perfect test bed for parametric scattering experiment.…”

Directional lasing at high oblique angle from metasurface exhibiting multivalley dispersion

“…As a matter of fact, the multivalley dispersion and valley lasing demonstrated in this work are the most important building blocks to study polariton valleytronic physics [34,35]. Indeed, it has been recently predicted that strong cou-pling regime with W-shaped dispersion would lead to Bose Einstein condensation at the valley extrema [35]. The formation of such macroscopic bosonic states at the valley extrema will pave the way to study spontaneous symmetry breaking, two-mode squeezing [34] and Josephson oscillation in momentum space [36].…”

“…This will be achieved by either working at cryogenic temperature or with quantum wells of highbinding energy excitons (GaN, ZnO, transition metal dichancogenides and perovskites) [33]. As a matter of fact, the multivalley dispersion and valley lasing demonstrated in this work are the most important building blocks to study polariton valleytronic physics [34,35]. Indeed, it has been recently predicted that strong cou-pling regime with W-shaped dispersion would lead to Bose Einstein condensation at the valley extrema [35].…”