Dark solitons in the condensate of exciton polaritons in semiconductor microcavities under nonresonant optical excitation

The first-order spatial correlation function $g^{(1)}(r_{12})$ and the polariton density distribution in the condensate of quasi-two-dimensional exciton polaritons formed in a high-Q semiconductor microcavity pillar under nonresonant optical pumping are investigated. It is found that the correlation function in certain regions of the micropillar decreases abruptly with increasing condensate density. It is shown that this behavior of the correlation function is caused by the formation of a localized dark soliton in these regions. A deep minimum of the polariton density and a shift in the phase of the condensate wavefunction by $\pi$ occur within the soliton localization area.