Ref HAL: hal-01909535_v1
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We will discuss the behavior of one or more elementary quantum system (atom, molecules,quantum dot, . . . ) interacting with a stationary, simple and rich electromagnetic environmentout of thermal equilibrium: The electromagnetic field is produced by a simple configuration ofmacroscopic objects held at thermal equilibrium at different temperatures. We will show howthe internal atomic dynamics can be deeply affected by the non equilibrium configurationleading to unexpected phenomena like a spontaneous inversion of population, new coolingmechanisms obtained by heating the system [1], and the possibility to create and protect entanglementin a stationary and robust way [2]. Finally, we will discuss how this system maydirectly allow the realization of atomic quantum thermal machines, with high efficiency and agenuine quantum behavior [3].------------[1] B. Bellomo, R. Messina, and M. Antezza, Europhys. Lett. 100, 20006 (2012)[2] B. Bellomo and M. Antezza, Europhys. Lett. 104, 10006 (2013)[3] B. Leggio, B. Bellomo, and M. Antezza, Phys. Rev. A 91, 012117 (2015)

Ref HAL: hal-01909530_v1
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We will discuss the behavior of one or more elementary quantum system (atom, molecules, quantum dot, …) interacting with a stationary, simple and rich electromagnetic environment out of thermal equilibrium: The electromagnetic field is produced by a simple configuration of macroscopic objects held at thermal equilibrium at different temperatures. We will show how the internal atomic dynamics can be deeply affected by the non equilibrium configuration leading to unexpected phenomena like a spontaneous inversion of population, new cooling mechanisms obtained by heating the system, and the possibility to create and protect entanglement in a stationary and robust way. Finally, we will discuss how this system may directly allow the realization of atomic quantum thermal machines, with high efficiency and a genuine quantum behavior.

Commentaires: General Theory-Experimental Colloquium of the Physics Department, Oldenburg University

Ref HAL: hal-01318661_v1
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We calculate the Casimir-Lifshitz pressure in a system consisting of two different one-dimensional dielectric lamellar gratings having two different temperatures and immersed in an environment having a third temperature. The calculation of the pressure is based on the knowledge of the scattering operators, deduced using the Fourier modal method. The behavior of the pressure is characterized in detail as a function of the three temperatures of the system as well as the geometrical parameters of the two gratings. We show that the interplay between nonequilibrium effects and geometrical periodicity offers a rich scenario for the manipulation of the force. In particular, we find regimes where the force can be strongly reduced for large ranges of temperatures. Moreover, a repulsive pressure can be obtained, whose features can be tuned by controlling the degrees of freedom of the system. Remarkably, the transition distance between attraction and repulsion can be decreased with respect to the case of two slabs, implying an experimental interest for the observation of repulsion.

Ref HAL: hal-01318487_v1
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We calculate the Casimir-Lifshitz pressure in a system consisting of two different one-dimensional dielectric lamellar gratings having two different temperatures and immersed in an environment having a third temperature [1]. The calculation of the pressure is based on the knowledge of the scattering operators, deduced using the Fourier modal method. The behavior of the pressure is characterized in detail as a function of the three temperatures of the system as well as the geometrical parameters of the two gratings. We show that the interplay between nonequilibrium effects and geometrical periodicity offers a rich scenario for the manipulation of the force. In particular, we find regimes where the force can be strongly reduced for a large range of temperatures. Moreover, a repulsive pressure can be obtained, whose features can be tuned by controlling the degrees of freedom of the system. Remarkably, the transition distance between attraction and repulsion can be decreased with respect to the case of two slabs, implying an experimental interest for the observation of repulsion.

Ref HAL: hal-01245998_v1
DOI: 10.1103/PhysRevA.92.062504
WoS: 000366730400001
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21 Citations
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We derive the explicit expression for the Casimir energy between a sphere and a one-dimensional grating in terms of the sphere and grating reflection matrices. This expression is valid for arbitrary materials, sphere radius, and grating geometric parameters. We then numerically calculate the Casimir energy between a metallic (gold) sphere and a dielectric (fused silica) lamellar grating at room temperature, and we explore its dependence on the sphere radius, grating-sphere separation, and lateral displacement. We quantitatively investigate the geometrical dependence of the interaction, which is sensitive to the grating height and filling factor, and we show how the sphere can be used as a local sensor of the Casimir force geometric features. Toward that end, we mostly concentrate on separations and sphere radii of the same order of the grating parameters (here of the order of1 μm).We also investigate the lateral component of the Casimir force, resulting from the absence of translational invariance. We compare our results with those obtained within the proximity force approximation (PFA). When applied to the sphere only, the PFA overestimates the strength of the attractive interaction, and we find that the discrepancy is larger in the sphere-grating than in the sphere-plane geometry. On the other hand, when the PFA is applied to both the sphere and the grating, it provides a better estimate of the exact results, simply

Ref HAL: hal-01235704_v1
DOI: 10.1209/0295-5075/112/40004
WoS: 000367165100004
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3 Citations
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We propose a configuration of a single three-level quantum emitter embedded in a non-equilibrium steady electromagnetic environment, able to stabilize and control the local temperatures of a target system it interacts with, consisting of a collection of coupled two-level systems.The temperatures are induced by dissipative processes only, without the need of further external couplings for each qubit. Moreover, by acting on a set of easily tunable geometric parameters, we demonstrate the possibility to manipulate and tune each qubit temperature independently over a remarkably broad range of values. These findings address one standard problem in quantum-scale thermodynamics, providing a way to induce a desired distribution of temperature among interacting qubits and to protect it from external noise sources.