Eur. Phys. J. D (2014) 68: 298
https://doi.org/10.1140/epjd/e2014-50266-4

Regular Article

Nonlocal defect solitons in parity-time-symmetric superlattices with defocusing nonlinearity

¹ Department of Physics, Guangdong University of Education, Guangzhou 510303, P.R. China
² Faculty of Information Engineering, Guangdong University of Technology, Guangzhou 510006, P.R. China
³ State Key Laboratory of Optoelectronic Materials and Technologies, Sun Yat-sen University, Guangzhou 510275, P.R. China

^a e-mail: lihuagang@gdei.edu.cn

Received: 1 April 2014
Received in final form: 25 July 2014
Published online: 16 October 2014

Abstract

We report on the nonlocal fundamental defect soliton in parity-time (PT)-symmetric superlattices with defocusing nonlinearity. For positive defect, soliton exist in the second gap, the first gap and the semi-infinite gap. They can be stable in the low power region in the first gap and semi-infinite gap. For negative defect, defect solitons only exist in the second gap, and can also be stable in the low power region. The degree of nonlocality can significantly affect the stability of these defect solitons. We also study the transverse power-flow of these defect solitons in the PT-symmetric superlattices.