Nonlocal soliton in non-parity-time-symmetric coupler

Parity-time (PT) symmetric is not a necessary condition for achieving real spectrum and some studies about realizing spectra in non-PT-symmetric systems with arbitrary gain–loss profiles have been presented recently. By tuning the free parameters potentials, phase transition could also be induced. Above point, discrete complex eigenvalues bifurcate out from continuous interior of spectrum. In this work, we investgate existence stability solitons nonlocal nonlinear couplers potentials both below above transition. There are several linear system used here. With square-operator iteration method, find that different families solitions can eigenvalues. Moreover, linear-stability analysis collaborated direct numerical propagation simulations demonstrates stable range parameter values. first address cases To specific, when fix coupling coefficient vary degree nonlocality, it’s found fundamental solitons, dipole tripolar quadrupole largest,the second-largest, third-largest fifth-largest eigenvalue, respectively. These all low power region. an increase region shrinks while it widens multiplole solitons. At same time, increases nonlocality. varying coefficient, arrangement soliton emerging interval changed. For example, third-or fourth-largest eigenvalue fifth largest eigenvalue. transition,the unstable high but moderate The increasing We family bifurcates second-largest unstable. addition, emerge as conjugation pairs.