Thermalizing Quantum Machines: Dissipation and Entanglement

TLDR

The interplay of quantum and classical information processes that give rise to practical irreversibility is discussed. The study investigates the relaxation of a quantum system toward thermal equilibrium and fully characterizes the family of thermalizing machines. The authors model a qubit system that equilibrates through successive two‑qubit interactions with reservoir qubits, employing quantum‑information tools. The analysis reveals a complete characterization of thermalizing machines and a tight link between dissipation, fluctuations, and maximal entanglement they can generate.

Abstract

We study the relaxation of a quantum system towards the thermal equilibrium using tools developed within the context of quantum information theory. We consider a model in which the system is a qubit, and reaches equilibrium after several successive two-qubit interactions (thermalizing machines) with qubits of a reservoir. We characterize completely the family of thermalizing machines. The model shows a tight link between dissipation, fluctuations, and the maximal entanglement that can be generated by the machines. The interplay of quantum and classical information processes that give rise to practical irreversibility is discussed.