EMISSION-SPECTRUM IN DRIVEN 2-LEVEL SYSTEMS

We study the dynamic behavior of an electron in a two-level system dri ven by dc-ac electric fields. Analytical solutions for the dipole mome nt and its emission spectrum are obtained under the approximation of t he high-frequency driving case, from which the physical property of th e system is found to be controlled by the field parameters. A number o f time-periodic and quasiperiodic phenomena as well as their signature in the emission spectrum are revealed. By making the proper choice of the field parameters, it is possible to selectively eliminate some co mponents in the spectrum. The analytical findings are confirmed numeri cally. [S1050-2947(98)01108-1].