We study the steady state behaviour of a confined quantum Brownian particle subjected to a space-dependent, rapidly oscillating time-periodic force. To leading order in the period of driving, the result of the oscillating force is an effective static potential which has a quantum dissipative contribution,
VQD, which adds on to the classical result. This is shown using a coherent state representation of bath oscillators.
VQD is evaluated exactly in the case of an Ohmic dissipation bath. It is strongest for intermediate values of the damping, where it can have pronounced effects.
Chandrasekhar's phenomenological theory of brownian motion is transcribed to the quantum regime. The statistics used is that of Boltzmann but the free particle was treated, in addition, with Fermi-Dirac statistics followed by some discussion relating to the measurements of low temperatures. Difficulties arising from the dissipative processes involved are by-passed with the aid of a new methodology enabling one to obtain a propagator in configuration space, which embraces single-particle dissipative forces. This sort of propagator is in turn used for the construction of a type of a nonequilibrium density matrix for the quantum brownian particle. Exact nonequilibrium density matrices for the free and the harmonically bound brownian particles under the influence of external time dependent forces are obtained. Finally, a quantum Fokker-Planck type equation for the general brownian particle is derived. The analysis proceeds via functional integration.