Modulational instability and soliton generation in chiral Bose-Einstein condensates with zero-energy nonlinearity

TL;DR

This paper investigates modulational instability in chiral Bose-Einstein condensates with zero-energy nonlinearity, revealing how current nonlinearity influences soliton formation and propagation in ring-shaped setups through analytical and numerical methods.

Contribution

It introduces the concept of zero-energy nonlinearity in chiral condensates and analyzes its effect on modulational instability and soliton dynamics.

Findings

Current nonlinearity partly suppresses MI driven by cubic self-focusing.

MI generates trains of stochastically interacting chiral solitons.

In ring setups, MI produces a single traveling solitary wave whose direction depends on the current nonlinearity.

Abstract

By means of analytical and numerical methods, we address the modulational instability (MI) in chiral condensates governed by the Gross-Pitaevskiiequation including the current nonlinearity. The analysis shows that this nonlinearity partly suppresses off the MI driven by the cubic self-focusing, although the current nonlinearity is not represented in the system's energy (although it modifies the momentum), hence it may be considered as zero-energy nonlinearity. Direct simulations demonstrate generation of trains of stochastically interacting chiral solitons by MI. In the ring-shaped setup, the MI creates a single traveling solitary wave. The sign of the current nonlinearity determines the direction of propagation of the emerging solitons.