arXiv subjects

M. Misko

Publications and source records attributed to M. Misko.

2 recordsLinked to original sources

arXiv2025

Kardar-Parisi-Zhang universality in optically induced lattices of exciton-polariton condensates

We investigate space-time coherence in one-dimensional lattices of exciton-polariton condensates formed by fully reconfigurable non-resonant optical pumping. Starting from an open-dissipative Gross-Pitaevskii equation with deterministic reservoir kinetics and stochastic condensate noise, we derive a discrete complex-field model that incorporates coherent tunnelling, reservoir-mediated dissipative coupling and gain-saturation non-linearity. Adiabatic elimination of fast density fluctuations reveals a wedge-shaped region in the complex hopping plane where the coarse-grained phase dynamics reduces to the Kardar-Parisi-Zhang (KPZ) equation. By computing high-resolution phase diagrams of the temporal and spatial scaling exponents we pinpoint the boundaries separating the KPZ domain from the Edwards-Wilkinson (EW) regime. Large-scale graphics processing unit (GPU) simulations of chains containing up to $N=2000$ condensates confirm these predictions: inside the wedge the exponents converge to $\beta_{N}=\textbf{0.329}(3)\!\approx\!1/3$ and $\chi_{N}=\textbf{0.504}(4)\!\approx\!1/2$, whereas outside it the dynamics moves away from KPZ and ultimately flows toward the EW fixed point, although finite system size and finite observation time may yield intermediate effective exponents. These results pave the way to the implementation of ultrafast KPZ-simulators based on one-dimensional arrays of exciton-polariton condensates.

cond-mat.mes-hall↗

arXiv2023

Thermalization rate of polaritons in strongly-coupled molecular systems

Polariton thermalization is a key process in achieving light-matter Bose--Einstein condensation, spanning from solid-state semiconductor microcavities at cryogenic temperatures to surface plasmon nanocavities with molecules at room temperature. Originated from the matter component of polariton states, the microscopic mechanisms of thermalization are closely tied to specific material properties. In this work, we investigate polariton thermalization in strongly-coupled molecular systems. We develop a microscopic theory addressing polariton thermalization through electron-phonon interactions (known as exciton-vibration coupling) with low-energy molecular vibrations. This theory presents a simple analytical method to calculate the temperature-dependent polariton thermalization rate, utilizing experimentally accessible spectral properties of bare molecules, such as the Stokes shift and temperature-dependent linewidth of photoluminescence, in conjunction with well-known parameters of optical cavities. Our findings demonstrate qualitative agreement with recent experimental reports of nonequilibrium polariton condensation in both ground and excited states, and explain the thermalization bottleneck effect observed at low temperatures. This study showcases the significance of vibrational degrees of freedom in polariton condensation and offers practical guidance for future experiments, including the selection of suitable material systems and cavity designs.

quant-ph↗