Frequency domain analysis of open two-state quantum systems

A two-state open quantum system composed of identical noninteracting particles, excited by a sinusoidal TEM electromagnetic wave and in contact with a thermal bath of an infinite thermal capacitance, is considered as a model for a typical nano circuit component working under linear conditions. Its steady state performance can be analyzed to any degree of accuracy by the Harmonic Balance Technique. It is shown that the power delivered to the bath, which in turn influences the small signal active performance, only depends on the even harmonics. This is the basis for implementing improved equivalent circuits.