Coherent Topological Polariton Laser

Abstract

Topological concepts have been applied to a wide range of fields in order to successfully describe the emergence of robust edge modes that are unaffected by scattering or disorder. In photonics, indications of lasing from topologically protected modes with improved overall laser characteristics were observed. Here, we study exciton-polariton microcavity traps that are arranged in a one-dimensional Su-Schrieffer-Heeger lattice and form a topological defect mode from which we unequivocally observe highly coherent polariton lasing. Additionally, we confirm the excitonic contribution to the polariton lasing by applying an external magnetic field. These systematic experimental findings of robust lasing and high temporal coherence are meticulously reproduced by a combination of a generalized Gross-Pitaevskii model and a Lindblad master equation model. Thus, by using the comparatively simple SSH geometry, we are able to describe and control the exciton-polariton topological lasing, allowing for a deeper understanding of topological effects on microlasers.

Room-Temperature Topological Polariton Laser in an Organic Lattice

“…40 Importantly, the defect always remains well within the topological gap, even when assuming a near-zero blue shift of the bulk modes. 20,45 It is important to note that the linear configuration used in this work easily allows for the realization of a domain boundary defect, while in the typically employed polariton zigzag SSH chains 20,44,45 so far only edge defects could be studied. Since the linear chain easily allows for both defect types, we have performed a similar nonresonant pulsed laser excitation experiment on the topological edge defect, characterized by a weak terminal bond.…”

“…As a result, a weakly bound edge pillar or a domain boundary defect having weak couplings in all directions ( t 1 < t 2 ) leads to a topological defect and a bulk Zak phase of γ = 1, whereas for the opposite case, the intercell hopping dominates the intracell hopping ( t 1 > t 2 ) of strongly coupled defects, which remains topologically trivial, and the Zak phase is γ = 0. Contrary to previous realizations of the SSH model for polaritons in zigzag chains relying on the orientation and coupling of P x , y modes, ,, we use a linear version for the lowest-energy S mode. Thus, the weak and strong intersite couplings are not achieved by an overlap asymmetry of higher-order modes but by the sheer difference in distance and overlap for circularly symmetric modes.…”

“…Further details about the SSH model are well demonstrated in refs. − and Supporting Information Section S1 in the context of the tight binding model.…”

Physics and Applications of High‐β Micro‐ and Nanolasers

“…Topological lasing in exciton‐polariton microcavity traps containing InGaAs QWs was realized in ref. [204].…”

Bloch Oscillations of Hybrid Light-Matter Particles in a Waveguide Array

“…The gradient needed to invoke Bloch oscillations in this waveguide array is oriented in y-direction, perpendicular to the propagation direction. While the use of Gross-Pitaevskii models has been fairly well established for exciton-polaritons in the past, we have successfully expanded these models to take into account sophisticated lattice potentials 32,33 . By tuning the gradient, coupling properties and excitation conditions, different regimes of propagation patterns can be achieved.…”