# Room-Temperature Exciton-Polariton Condensation in a Tunable   Zero-Dimensional Microcavity

**Authors:** Fabio Scafirimuto, Darius Urbonas, Ullrich Scherf, Rainer F. Mahrt,, and Thilo St\"oferle

arXiv: 1901.07403 · 2019-01-23

## TL;DR

This paper demonstrates room-temperature exciton-polariton condensation in a tunable zero-dimensional microcavity filled with organic polymers, showing threshold behavior, coherence, and potential for quantum fluid applications.

## Contribution

It introduces a novel zero-dimensional microcavity with tunable properties enabling exciton-polariton condensation at room temperature, a significant step forward in polariton research.

## Key findings

- Achieved polariton condensation at room temperature.
- Observed non-linear emission intensity and line narrowing.
- Confirmed coherence and ground state condensation.

## Abstract

We create exciton-polaritons in a zero-dimensional (0D) microcavity filled with organic ladder-type conjugated polymer in the strong light-matter interaction regime. Photonic confinement at wavelength scale is realized in the longitudinal direction by two dielectric Bragg mirrors and laterally by a sub-micron Gaussian-shaped defect. The cavity is separated into two parts allowing nanometer position control and enabling tuning of exciton and photon fractions of the polariton wavefunction. Polariton condensation is achieved with non-resonant, picosecond optical excitation at ambient conditions and evidenced by a threshold behavior with non-linear increase of the emission intensity, line narrowing and blue-shift of the emission peak. Furthermore, angular emission spectra show that condensation occurs in the ground state of the 0D-cavity, and first order coherence measurements reveal the coherent nature. These experiments open the door for polariton quantum fluids in complex external potentials at room temperature.

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Source: https://tomesphere.com/paper/1901.07403