Coherence and catalysis in the Jaynes-Cummings model

There has been substantial interest of late on the issue of coherence as a resource in quantum thermodynamics. To date, however, analyses have focussed on somewhat artificial theoretical models. We seek to bring these ideas closer to experimental investigation by examining the ``catalytic'' nature of quantum optical coherence. Here the interaction of a coherent state cavity field with a sequence of two-level atoms is considered, a state ubiquitous in quantum optics as a model of a stable, classical source of light. The Jaynes-Cummings interaction Hamiltonian is used, so that an exact solution for the dynamics can be formed, and the evolution of the atomic and cavity states with each atom-field interaction analysed. In this way, the degradation of the coherent state is examined as coherence is transferred to the sequence of atoms. The associated degradation of the coherence in the cavity mode is significant in the context of the use of coherence as a thermodynamic resource.