Thermodynamics of the Ramsey Zone

Author(s)

de Assis, Rogerio Jorge ; Diniz, Ciro Micheletti ; de Almeida, Norton Gomes ; Villas-Boas, Celso Jorge

• Document type: Journal article
• Source: Entropy; v. 25, n. 10, p. 10-pg., 2023-10-01.

Abstract

We studied the thermodynamic properties such as the entropy, heat (JQ), and work (JW) rates involved when an atom passes through a Ramsey zone, which consists of a mode field inside a low-quality factor cavity that behaves classically, promoting rotations on the atomic state. Focusing on the atom, we show that JW predominates when the atomic rotations are successful, maintaining its maximum purity as computed by the von Neumann entropy. Conversely, JQ stands out when the atomic state ceases to be pure due to its entanglement with the cavity mode. With this, we interpret the quantum-to-classical transition in light of the heat and work rates. Besides, we show that, for the cavity mode to work as a Ramsey zone (classical field), several photons (of the order of 106) need to cross the cavity, which explains its classical behavior, even when the inside average number of photons is of the order of unity. (AU)

• FAPESP's process: 21/04672-0 - Quantum thermal engines and nonequilibrium steady states
• Grantee: Rogério Jorge de Assis
• Support Opportunities: Scholarships in Brazil - Post-Doctoral
• FAPESP's process: 19/11999-5 - Collective effects on atomic systems, nuclear spins and cavity quantum electrodynamics
• Grantee: Celso Jorge Villas-Bôas
• Support Opportunities: Regular Research Grants