Entropic fluctuation theorems for the spin–fermion model

We study entropic fluctuations in the Spin–Fermion model describing an N-level quantum system coupled to several independent thermal free Fermi gas reservoirs. We establish the quantum Evans–Searles and Gallavotti–Cohen fluctuation theorems and identify their link with entropic ancilla state tomography and quantum phase space contraction of non-equilibrium steady state. The method of proof involves the spectral resonance theory of quantum transfer operators developed by the authors in previous works.