Solitons and Soliton Molecules in two Nonlocal Alice-Bob Fifth-Order KdV Systems

Soliton molecules were first discovered in optical systems and they have recently received reinvigorating scientific interests in physics and beyond. In this paper, we mainly study a typical model of nonlocal fifth-order KdV system. First, the model is obtained by using parity, time reversal invariance and Lax pairs. Secondly, we obtain soliton solutions by means of the bilinear method. Finally, based on the N-soliton solution, soliton molecules can be obtained via the velocity resonance mechanism. Especially, some soliton molecules have been observed successfully in the laboratory.