Coherent heat exchange in a prethermalizing open quantum system

We investigate a simple model exhibiting a prethermal phase, i.e., a metastable state that emerges before full thermalization, through the framework of quantum stochastic thermodynamics. We explore the effects of quantum coherence in the energy eigenbasis of the initial state of the system on the process of heat exchange with a bath, and their contribution to entropy production as quantified by a heat-exchange fluctuation theorem. Such a relation is derived using the end-point measurement scheme, a protocol that accounts for initial quantum coherence in the statistics of energy exchanges resulting from a nonequilibrium process. We compare these results with those obtained from the widely used two-point measurement scheme, which, by construction, fails to capture such quantum effects.