Modulation instability and solitary wave formation in two-component Bose-Einstein condensates

TL;DR

This paper explores how modulation instability in two-component Bose-Einstein condensates leads to the formation of vector solitary waves, revealing complex nonlinear dynamics influenced by coupling constants.

Contribution

It provides a detailed numerical analysis of solitary wave formation in two-component BECs, highlighting the role of coupling signs and drawing analogies with collapse phenomena.

Findings

Unstable modulation results in various vector solitary waves.

Dynamics depend on the sign of intra- and intercomponent couplings.

Analogies with collapse dynamics in single-component condensates.

Abstract

We investigate nonlinear dynamics induced by the modulation instability of a two-component mixture in an atomic Bose-Einstein condensate. The nonlinear dynamics is examined using numerical simulations of the time-dependent coupled Gross-Pitaevskii equations. The unstable modulation grows from initially miscible condensates into various types of vector solitary waves, depending on the combinations of the sign of the coupling constants (intracomponent and intercomponent). We discuss the detailed features of the modulation instability, dynamics of solitary wave formation, and an analogy with the collapsing dynamics in a single-component condensate with attractive interactions.