Quantum Oscillator in a Blackbody Radiation Field
G. W. Ford, J. T. Lewis, Robert F. O’Connell · Physical Review Letters · 1985
The quantum Langevin equation is used to calculate an exact expression for the free energy of a quantum oscillator interacting, via dipole coupling, with a blackbody radiation field. In particular, we obtain a temperature-dependent shift in the free energy. This result may then be used to obtain corresponding results for the energy, the partition function, and other thermodynamic quantities.