Higher-order dark solitons and oscillatory dynamics in microcavity polariton condensates

TL;DR

This paper demonstrates the stable existence of higher-order dark solitons and their oscillatory dynamics in microcavity polariton condensates under optical confinement, revealing complex soliton interactions and new stable density dips.

Contribution

It introduces the numerical demonstration of higher-order dark solitons and dark oscillators in microcavity polariton condensates with optical trapping, highlighting novel stable soliton states.

Findings

Higher-order dark solitons can be stabilized in optical potential traps.

Multiple dark soliton states can be excited simultaneously using optical lattices.

Stable density dips can form from interactions of trapped dark solitons.

Abstract

Dark solitons carrying quantized phase information arouse great interest in different nonlinear systems. A dark soliton in 1D can be stabilized in microcavity polariton condensates as a confinement is imposed on it to prevent its decay. Such a confinement can be realized by optical manners, i.e., by using optically induced potential traps. Under nonresonant excitation with spatially periodically modulated optical beams, we numerically demonstrate that besides fundamental dark solitons, higher-order dark solitons with multiple density minima and $\pi$-phase jumps can also stably survive in the potential (pump) valleys. Simultaneously exciting several orders of dark soliton states by properly choosing the lattice constant of the optical pump gives rise to dark oscillators. In some cases, the stably trapped dark solitons in adjacent pump valleys squeeze the condensate density between them and generate another type of density dips in the pump peak area. Surprisingly, such a density dip supports another stable dark soliton with a larger size which is essentially composed of two counter-propagating gray solitons.