Solitons in a chain of charge-parity-symmetric dimers

Abstract

We consider an array of dual-core waveguides, which represent an optical realization of a chain of dimers, with an active (gain-loss) coupling between the cores, opposite signs of discrete diffraction in the parallel arrays, and a phase-velocity mismatch between them (which is necessary for the stability of the system). The array provides an optical emulation of the charge-parity ($\mathcal{C}\mathcal{P}$) symmetry. The addition of the intracore cubic nonlinearity gives rise to several species of fundamental discrete solitons, which exist in continuous families, although the system is non-Hermitian. The existence and stability of the soliton families are explored by means of analytical and numerical methods. An asymptotic analysis is presented for the case of weak intersite coupling (i.e., near the anticontinuum limit), as well as weak coupling between cores in each dimer. Several families of fundamental discrete solitons are found in the semi-infinite gap of the system's spectrum, that have no counterparts in the continuum limit, as well as a branch which belongs to the finite band gap and carries over into a family of stable gap solitons in that limit. One branch develops an oscillatory instability above a critical strength of the intersite coupling, others being stable in their entire existence regions. Unlike solitons in conservative lattices, which are controlled solely by the strength of the intersite coupling, here fundamental-soliton families have several control parameters, one of which, viz., the coefficient of the intercore coupling in the active host medium, may be readily adjusted in the experiment by varying the gain applied to the medium.

arXiv comment11 pages, 8 figures

References in corpus (16)

• Unidirectional Invisibility induced by PT-Symmetric Periodic Structures
• Nonlinear waves in $\mathcal{P}\mathcal{T}$-symmetric systems
• Physical realization of $\mathcal{P}\mathcal{T}$-symmetric potential scattering in a planar slab waveguide
• Nonlinear switching and solitons in PT-symmetric photonic systems
• PT-Symmetric Electronics
• Stability of solitons in PT-symmetric couplers
• Optical solitons in $\mathcal{P}\mathcal{T}$-symmetric nonlinear couplers with gain and loss
• Spectral singularities and Bragg scattering in complex crystals
• Mechanical PT symmetry in coupled optomechanical systems
• Stability boundaries and collisions of two-dimensional solitons in PT-symmetric couplers with the cubic-quintic nonlinearity
• Test of Lorentz and CPT violation with Short Baseline Neutrino Oscillation Excesses
• One- and two-dimensional solitons in PT-symmetric systems emulating the spin-orbit coupling
• T and CPT Symmetries in Entangled Neutral Meson Systems
• CP symmetry in optical systems
• Systems that become $\mathcal{P}\mathcal{T}$ symmetric through interaction
• Breathing solitary-pulse pairs in a linearly coupled system

Cited by in corpus (3)

• Symmetry and Topology in Non-Hermitian Physics
• Dynamical control of solitons in a parity-time-symmetric coupler by periodic management
• Discrete solitons dynamics in $\mathcal{P}\mathcal{T}$-symmetric oligomers with complex-valued couplings