Bound and anti-bound soliton states for a quantum integrable derivative nonlinear Schrödinger model

Abstract

We find that localized quantum N-body soliton states exist for a derivative nonlinear Schrödinger (DNLS) model within an extended range of coupling constant (ξ_q) given by 0 < |ξ_q| < 1/ћtan(π/N−1). We also observe that soliton states with both positive and negative momentum can appear for a fixed value of ξ_q. Thus the chirality property of classical DNLS solitons is not preserved at the quantum level. Furthermore, it is found that the solitons with positive (negative) chirality have positive (negative) binding energy.