Berlin 2024 – scientific programme

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HL: Fachverband Halbleiterphysik

HL 19: Quantum Dots and Wires: Optics I

HL 19.12: Talk

Tuesday, March 19, 2024, 12:45–13:00, EW 202

Highly coherent GaAs-based microcavity polaritons dots at 200 K — •Ismael dePedro-Embid, Alexander Kuznetsov, Klaus Biermann, and Paulo Santos — Paul-Drude-Institut für Festkörperelektronik, Berlin, Deutschland

Microcavity (MC) polaritons, serve as an exceptional bridge between condensed matter and photonic systems. Achieving precise control over their spatial distribution, stability, and coherence is crucial for unlocking their full potential in practical applications. This can be achieved by creating zero-dimensional polariton dots by lateral confinement within the MC spacer. In this study, we investigate the effects of lateral confinement on the energy and temporal coherence of MC polaritons in (Al, Ga) As intracavity dots at temperatures up to 200 K, which are much higher than the usually studied temperatures of around 10 K for this material system. Our experimental results show that the spectral linewidths of the confined polariton states are substantially narrower than their unconfined counterparts, demonstrating that confinement significantly enhances the temporal coherence across a broad range of dot dimensions. A comprehensive analysis of the temperature dependence of the resonances points to protection from low-energy acoustic phonon scattering as the primary mechanism for linewidth narrowing. The latter underscores the effectiveness of lateral confinement as a method for engineering polariton-phonon interaction at high temperatures. This work thus establishes the feasibility of GaAs-based polariton structures with long temporal coherence at high temperatures.

Keywords: Polariton; Optical microcavity; GaAs