(color online) Stationary solitons with ω_s = 1, β = −1, and α = 0.5. Black: h = 0.25; green: h = 0.5. (a) Fourier space. (b) Physical space. Note that the background in panel (a) is nonzero. The property of nonlinear hopping α is displayed in panel (b), and the value of F(nh) tends to be zero as | n | → ∞ in physical space. The values of | F ( nh ) | in each line are marked by signs of circles and boxes, respectively.