Trade-off between coherence and heat in a non-Markovian dephasing dynamics
Abstract
How quantum coherence influences thermodynamic behavior remains an open question in quantum thermodynamics. Here we investigate this relation within the pure dephasing framework, where a central qubit interacts with a finite Ising-like spin environment. Although the system's internal energy remains constant, the interaction induces decoherence and gives rise to nontrivial thermodynamic features. Within the two-point measurement approach, we show that the heat dissipated into the environment matches the coherent energy contribution appearing in a reformulated first law of quantum thermodynamics. Numerical calculations reveal oscillatory coherence dynamics, with revivals associated with information backflow and non-Markovian effects, as quantified by the Breuer-Laine-Piilo measure. We find that heat and coherence exhibit intertwined temporal behavior, with enhanced heat dissipation during coherence decay and reduced heat during revivals. These results suggest a connection between coherence dynamics and thermodynamic quantities in finite, closed composite systems undergoing pure dephasing.
Cite
@article{arxiv.2603.27387,
title = {Trade-off between coherence and heat in a non-Markovian dephasing dynamics},
author = {Marino P. Lenzarini and Diogo O. Soares-Pinto},
journal= {arXiv preprint arXiv:2603.27387},
year = {2026}
}