We derive an expression for the fluctuations of the energy in an open quantum system undergoing a nontrivial evolution. The statistics of energy are constructed by means of a two-point measurement process when the system has been evolved by a completely positive and trace-preserving map. The statistics depend only on the state of the system and the dynamical map generating the evolution. In particular, we consider the Tasaki–Crooks fluctuation theorem, where a unitary evolution is replaced by a quantum channel. Our construction of a backward process using an ancilla sheds important light on the mathematical structure at play when nonunital channels are considered in quantum thermodynamics.
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Research Article| December 28 2021
Fluctuation theorem for nonunital dynamics
Special Collection: Quantum Thermodynamics
J. Goold, K. Modi; Fluctuation theorem for nonunital dynamics. AVS Quantum Sci. 1 December 2021; 3 (4): 045001. https://doi.org/10.1116/5.0065123
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