Thermal Recall: MemoryAssisted Markovian Thermal Processes
Abstract
We develop a resourcetheoretic framework that allows one to bridge the gap between two approaches to quantum thermodynamics based on Markovian thermal processes (which model memoryless dynamics) and thermal operations (which model arbitrarily nonMarkovian dynamics). Our approach is built on the notion of memoryassisted Markovian thermal processes, where memoryless thermodynamic processes are promoted to nonMarkovianity by explicitly modeling ancillary memory systems initialized in thermal equilibrium states. Within this setting, we propose a family of protocols composed of sequences of elementary twolevel thermalizations that approximate all transitions between energyincoherent states accessible via thermal operations. We prove that, as the size of the memory increases, these approximations become arbitrarily good for all transitions in the infinite temperature limit, and for a subset of transitions in the finite temperature regime. Furthermore, we present solid numerical evidence for the convergence of our protocol to any transition at finite temperatures. We also explain how our framework can be used to quantify the role played by memory effects in thermodynamic protocols such as work extraction. Finally, our results show that elementary control over two energy levels at a given time is sufficient to generate all energyincoherent transitions accessible via thermal operations if one allows for ancillary thermal systems.
 Publication:

PRX Quantum
 Pub Date:
 October 2023
 DOI:
 10.1103/PRXQuantum.4.040304
 arXiv:
 arXiv:2303.12840
 Bibcode:
 2023PRXQ....4d0304C
 Keywords:

 Quantum Physics
 EPrint:
 20 pages, 14 figures. Substantially extended results with new sections and application. Published version