Ultrafast exciton-polariton scattering towards the Dirac points

TL;DR

This paper investigates ultrafast polariton scattering in a 2D hexagonal lattice, revealing how chirality and loop diagrams influence scattering times, with implications for designing low-threshold polariton lasers.

Contribution

It introduces a detailed theoretical analysis of nonlinear polariton scattering, emphasizing the importance of chirality and infinite-order loop diagrams in a hexagonal lattice.

Findings

Polariton scattering time towards Dirac points can be significantly reduced.

Chirality and loop diagrams are crucial for accurate self-energy evaluation.

Potential for engineering low-threshold polariton lasers.

Abstract

Using the Feynman-Dyson diagram technique, we study nonlinear polariton-polariton scattering in a two-dimensional micropillar-based optical superlattice with hexagonal symmetry. We demonstrate that both the emerging polariton chirality and the loop Feynman diagrams up to infinite order should be strictly accounted for in the evaluation of the self-energy of the system. Further, we explicitly show that in such a design the time of polariton scattering towards the Dirac points can be drastically decreased which can be used, for instance, in engineering novel classes of polariton lasers with substantially reduced thresholds.