The Harmonic Balance Technique Analysis of Open Quantum Systems

The Harmonic Balance Technique (HBT) is used to analyze the steady state performance of a two–state quantum system interacting with a classical sinusoidal electromagnetic wave and with a thermal bath at a fixed temperature. The linear time–variant differential equations describing such a system can be solved to any number of harmonics and the results can be compared with those obtained with the classical RWA approximation, thus evidencing the validity limits of the latter.