title: Gray solitons in parity-time symmetric potentials.
abstract: We numerically study the gray solitons in parity-time (PT) symmetric potentials. Simulated results show that there are two kinds of gray solitons, the dip-shaped gray solitons and the hump-shaped solitons, and both of them can be stable. Hump-shaped solitons can always exist, but the grayness of a stable dip-shaped gray soliton should exceed a threshold value. More interesting, it is discovered that when propagating in PT symmetric potentials, the gray solitons have no transverse deviation, and this is a phenomenon different from the usual gray solitons.
authors.affiliation: Department of Physics, Guangdong University of Education, Guangzhou 510303, China.
authors.forename: Huagang
authors.initials: H
authors.lastname: Li
authors.forename: Zhiwei
authors.initials: Z
authors.lastname: Shi
authors.forename: Xiujuan
authors.initials: X
authors.lastname: Jiang
authors.forename: Xing
authors.initials: X
authors.lastname: Zhu