Extending the validity range of quantum optical master equations

Abstract

This paper derives master equations for an atomic two-level system for a large set of unitarily equivalent Hamiltonians without employing the rotating-wave and certain Markovian approximations. Each Hamiltonian refers to physically different components as representing the ``atom'' and as representing the ``field'' and hence results in a different master equation, when assuming a photon absorbing environment. It is shown that the master equations associated with the minimal-coupling and the multipolar Hamiltonians predict enormous stationary state narrow-band photon emission rates, even in the absence of external driving, for current experiments with single quantum dots and color centers in diamond. These seem to confirm that the rotating-wave Hamiltonian identifies the components of the atom-field system most accurately.