Aurélien Trichet | Searcharxiv

arXiv2013

Long range correlations in a 97% excitonic one-dimensional polariton condensate

We report on the realization of an out-of-equilibrium polariton condensate under pulsed excitation in a one-dimensional geometry. We observe macroscopic occupation of a polaritonic mode with only 3% photonic fraction, and a nature strikingly close to that of a bare exciton condensate. With the help of this tiny photonic fraction, the condensate is found to display first-order coherence over distances as large as 10 microns. Based on a driven-dissipative mean field model, we find that the correlations length is limited by the effects of a shallow disorder under non-equilibrium conditions.

cond-mat.mes-hall↗

arXiv2010

One-dimensional ZnO exciton polaritons with negligible thermal broadening at room temperature

Phonon damping is the main source of pure dephasing in the solid state, limiting many fundamental quantum effects to low temperature observations. Here we show how excitons in semiconductors can be totally decoupled from the phonon bath, even at room temperature, thanks to their strong interaction with photons. To do so, we investigated ZnO microwires, a new semiconductor nanostructure made of large band-gap material where the light can be trapped and guided into whispering gallery modes. In this system, the very large coupling regime between exciton and photon results in unusual exciton-polariton of one-dimensional character and Rabi splitting as large as 300meV. We find that polariton modes of excitonic fraction up to 75% exhibit no thermal broadening up to room temperature. We show that this remarkable behavior is due to the very large Rabi splitting as compared to the LO phonon energy.

cond-mat.mes-hall↗