Quantum chaos of periodically pulsed systems: Underlying complete integrability

The integrability underlying the quantum mechanics of noninte- grable pulsed systems is examined along the line exploited by Nakamura and Lakshmanan [Phys. Rev. Lett. 57, 1661 (1986)]. Coupled dynamical equations for both quasienergies and quasieigenfunctions (rather than matrix elements) with a nonintegrability parameter {λ} taken as ``time'' are shown to be reduced to a classical Sutherland's system with internal complex-vector space. Their complete integrability together with constants of motion are also exhibited.