Metastable quasienergy positions and widths for time-periodic Hamiltonians by the complex-coordinate method

A formulation according to which the positions and widths of metastable quasienergy states can be obtained for any time-periodic field within the framework of the finite-basis-set (real or complex) approximation is presented. A numerical example is given to illustrate the potential use of the proposal method in the study of the dynamics of laser-driven systems and of the dynamics of time-periodic classical chaotic Hamiltonians.