TY - JOUR

T1 - Solitons in a chain of charge-parity-symmetric dimers

AU - Kirikchi, O. B.

AU - Malomed, Boris A.

AU - Karjanto, N.

AU - Kusdiantara, R.

AU - Susanto, H.

N1 - Funding Information:
R.K. gratefully acknowledges financial support from the Indonesia Endowment Fund for Education (Lembaga Pengelolaan Dana Pendidikan, LPDP) through Grant No. S-34/LPDP.3/2017. B.A.M. is supported, in part, by the Joint Program in Physics between the NSF and the Binational (US-Israel) Science Foundation through Project No. 2015616, and by the Israel Science Foundation through Grant No. 12876/17. N.K. acknowledges supports from the SKKU Samsung Intramural Research Fund No. 2016-1299-000 and the National Research Foundation of Korea through Grant No. NRF-2017-R1C1B5-017743. B.A.M. and N.K. appreciate the hospitality of the Department of Mathematical Sciences at the University of Essex (Colchester, UK).
Publisher Copyright:
© 2018 American Physical Society.

PY - 2018/12/26

Y1 - 2018/12/26

N2 - 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 (CP) 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, which 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.

AB - 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 (CP) 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, which 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.

UR - http://www.scopus.com/inward/record.url?scp=85059406841&partnerID=8YFLogxK

U2 - 10.1103/PhysRevA.98.063841

DO - 10.1103/PhysRevA.98.063841

M3 - Article

AN - SCOPUS:85059406841

SN - 2469-9926

VL - 98

JO - Physical Review A

JF - Physical Review A

IS - 6

M1 - 063841

ER -