HIGH-ORDER SPLIT-STEP EXPONENTIAL METHODS FOR SOLVING COUPLED NONLINEAR SCHRODINGER-EQUATIONS

Numerical integration schemes for coupled time-dependent nonlinear Sch rodinger equations are examined using exponential splitting step metho ds. Exponentiation of the nonlinear potential term is reduced to the e xponential of a kinetic energy term which can be calculated by fast Fo urier transforms. High-order iteration schemes involving a minimum num ber of product operators are shown to yield highly accurate amplitude and phase. These new splitting methods are shown to be highly efficien t both with respect to accuracy and integration time.