Quantum Dynamics of Interacting dissipative oscillators: A novel scheme

Abstract

We investigate the dynamics of interacting quantum harmonic oscillators coupled to thermal reservoirs under the influence of an external driving field. In a novel theoretical scheme, we first analyze the case of two interacting oscillators, each coupled to its own thermal reservoir, with an external source applied to the first oscillator. By diagonalizing the total Hamiltonian through successive Bogoliubov transformations, we obtain explicit expressions for the oscillator energies. A key finding is that off resonance, the energy of the second oscillator grows unboundedly, whereas on resonance, it remains bounded and periodic. We then derive the Husimi functions for both oscillators and the reduced Husimi functions for initially separable coherent and number states. The shift of the Husimi function's maximum away from the origin at zero temperature confirms continuous energy gain under specific parameter conditions. An explicit formula for the reduced density matrix components in the number state basis is also provided. Finally, we generalize the model to $n$ interacting oscillators in a thermal medium driven by a classical field. For the three-oscillator case, we show that on resonance, the energies of the first and third oscillators grow, while the energy of the second oscillator remains periodically bounded. These results offer insights into energy transfer and localization in coupled oscillator systems in thermal environments.