Formation and propagation of stable high-dimensional soliton molecules and breather molecules in a cold Rydberg atomic gas

TL;DR

This paper explores how stable high-dimensional optical soliton molecules and breather molecules form and propagate in a Rydberg atomic gas, revealing the roles of nonlocality and initial velocity in their stability and dynamics.

Contribution

It introduces a novel understanding of the formation regimes of soliton and breather molecules in nonlocal nonlinear media, emphasizing the importance of initial velocity and nonlocal interactions.

Findings

Long-range interactions stabilize soliton molecules without initial motion.

Initial velocity induces rotating and breathing soliton molecules.

Diverse lattice configurations of soliton molecules are achievable.

Abstract

We investigate the mechanisms of formation of stable (2+1)-dimensional optical soliton molecules (SMs) and breather molecules (BMs) in a Rydberg atomic gas, highlighting the distinct roles of nonlocality. The underlying giant, nonlocal nonlinearity induced via Rydberg electromagnetically induced transparency (EIT), supports diverse, large-size lattice SMs (rhombic, square, checkerboard, hexagonal lattice SMs). Crucially, we identify two distinct formation regimes: In the nonlocal regime, long-range interactions alone stabilize the SMs without requiring initial motion. In contrast, within the strongly nonlocal regime, an initial velocity is essential to generate a centrifugal force that counteracts the strong attraction, resulting in rotating SMs. Furthermore, specific initial velocities can induce a periodic breathing instability, leading to the formation of BMs. Our study offers a new scheme for engineering SMs with diverse configurations and opens new avenues for data processing and transmission in optical systems.