arXiv subjects

Camille Lombard Latune

Publications and source records attributed to Camille Lombard Latune.

3 recordsLinked to original sources

arXiv2023

Reply to "Comment on `Extending the laws of thermodynamics for arbitrary autonomous quantum systems'"

In his Comment [1], Philip Strasberg (PS) argues from the analysis of different examples that the framework we have presented in [2] does not recover known results of macroscopic textbook thermodynamics. Here, we show that such apparent contradictions disappear when the necessary assumptions the aforementioned known results pre-suppose are applied. Those assumptions concern the control ability of the observer, the nature of the described degree of freedom, or the scale of the systems. The ability to relax those assumptions is precisely a motivation of our framework, which can explore the capacity of quantum systems to exchange work and heat even at scales not captured by textbook thermodynamics. We take the opportunity of this reply to further expand on the use of our framework and its connections with traditional thermodynamics.

quant-ph↗

arXiv2023

Extending the laws of thermodynamics for arbitrary autonomous quantum systems

Originally formulated for macroscopic machines, the laws of thermodynamics were recently shown to hold for quantum systems coupled to ideal sources of work (external classical fields) and heat (systems at equilibrium). Ongoing efforts have been focusing on extending the validity of thermodynamic laws to more realistic, non-ideal energy sources. Here, we go beyond these extensions and show that energy exchanges between arbitrary quantum systems are structured by the laws of thermodynamics. We first generalize the second law and identify the associated work and heat exchanges. After recovering known results from ideal work and heat sources, we analyze some consequences of hybrid work and heat sources. We illustrate our general laws with microscopic machines realizing thermodynamic tasks in which the roles of heat and work sources are simultaneously played by elementary quantum systems. Our results open perspectives to understand and optimize the energetic performances of realistic quantum devices, at any scale.

quant-ph↗

arXiv2016

Quantum force estimation in arbitrary non-Markovian Gaussian bath

The force estimation problem in quantum metrology with an arbitrary non-Markovian Gaussian bath is considered. No assumptions are made on the bath spectrum and coupling strength with the probe. Considering the natural global unitary evolution of both bath and probe and assuming initial global Gaussian states we are able to solve the main issues of any quantum metrological problem: the best achievable precision determined by the quantum Fisher information, the best initial state and the best measurement. Studying the short time behavior and comparing to regular Markovian dynamics we observe an increase of quantum Fisher information. We emphasize that this phenomenon is due to the ability to perform measurements below the correlation time of the bath, activating non-Markovian effects. This brings huge consequences for the sequential preparation-and- measurement scenario as the quantum Fisher information becomes unbounded when the initial probe mean energy goes to infinity, whereas its Markovian counterpart remains bounded by a constant. The long time behavior shows the complexity and potential variety of non-Markovian effects, somewhere between the exponential decay characteristic of Markovian dynamics and the sinusoidal oscillations characteristic of resonant narrow bands.

quant-ph↗