Coupled Solitons for Quantum Communication and Metrology in the Presence of Particle Dissipation

Bright solitons represent natural information carriers for optical communication. However, particle losses create serious barriers to soliton implementation in quantum technologies for quantum communication and quantum metrology purposes. In this work, we consider a quantum coupled soliton problem in the presence of soliton particle dissipation and examine two suitable configurations for soliton coupling. The soliton Josephson junction (SJJ) and nonlinear soliton Josephson junction (NSJJ) models presume 1D soliton coupling in the transverse and longitudinal dimensions, respectively. We elucidate phase portraits both in the absence and presence of losses. For the latter case, we show that dynamical switching between macroscopic self-trapping and Rabi-like oscillation regimes occurs. For quantization of coupled-soliton parameters, we exploit the phase difference and particle-number-imbalance conjugated variables. In the presence of weak particle losses, we determine the characteristic frequencies of small-amplitude Rabi-like oscillations for these variables. In the adiabatic limit, we establish quantum properties of the soliton-population imbalance and phase difference. Relevant uncertainty relation is studied for the examined soliton junction models.