The Convergence of Symmetric Discretization Models for Nonlinear Schrodinger Equation in Dark Solitons' Motion

The Schrodinger equation is one of the most basic equations in quantum mechanics. In this paper, we study the convergence of symmetric discretization models for the nonlinear Schrodinger equation in dark solitons' motion and verify the theoretical results through numerical experiments. Via the second-order symmetric difference, we can obtain two popular space-symmetric discretization models of the nonlinear Schrodinger equation in dark solitons' motion: the direct-discrete model and the Ablowitz-Ladik model. Furthermore, applying the midpoint scheme with symmetry to the space discretization models, we obtain two time-space discretization models: the Crank-Nicolson method and the new difference method. Secondly, we demonstrate that the solutions of the two space-symmetric discretization models converge to the solution of the nonlinear Schrodinger equation. Additionally, we prove that the convergence order of the two time-space discretization models is O(h(2)+t(2)) in discrete L-2-norm error estimates. Finally, we present some numerical experiments to verify the theoretical results and show that our numerical experiments agree well with the proven theoretical results.