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(180) Production(s) de ANTEZZA M.
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Elementary quantum systems out of thermal equilibrium: From quantum thermalization to entanglement
Auteur(s): Antezza M.
Conférence invité: FQMT13 “Frontiers of Quantum and Mesoscopic Thermodynamics” (Prague, CZ, 2013-07-30)
Ref HAL: hal-01910035_v1
Exporter : BibTex | endNote
Résumé: We study the internal dynamics, the quantum thermalization and the entanglementof elementary quantum systems (one or two atoms) placed close to a body held at atemperature different from that of the surrounding radiation.Concerning the single atom dynamics [1,2], we derive general expressions for lifetimeand density matrix valid for bodies of arbitrary geometry and dielectric permittivity.Out of equilibrium, the thermalization process and steady states become both qualitativelyand quantitatively significantly different from the case of radiation at thermalequilibrium. For the case of a three-level atom close to a slab of finite thickness, wepredict the occurrence of population inversion and an efficient cooling mechanism forthe quantum system, whose effective internal temperature can be driven to values muchlower than both involved temperatures. Our results show that non-equilibrium configurationsprovide new promising ways to control the state of an atomic system.We also consider two two-level atomic quantum systems (qubits) [3]. While at thermalequilibrium the two-qubit dynamics is characterized by not entangled steady thermalstates, we show that absence of thermal equilibrium may bring to the generationof entangled steady states. Remarkably, this entanglement emerges from the two-qubitdissipative dynamic itself, without any further external action on the two qubits, suggestinga new protocol to produce and protect entanglement which is intrinsically robustto environmental effects.======================[1] Bruno Bellomo, Riccardo Messina, and Mauro Antezza, Europhys. Lett. 100, 20006(2012).[2] Bruno Bellomo, Riccardo Messina, Didier Felbacq, and Mauro Antezza, Phys. Rev.A 87, 012101 (2013).[3] Bruno Bellomo, and Mauro Antezza, arXiv:1304.2864 (2013).
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Near-field heat transfer between arbitrary bodies: from quantum thermalization to entanglement
Auteur(s): Antezza M.
(Séminaires)
Centre de physique des Houches (Les Houches, FR), 2013-06-12
Commentaires: Cours invité à Physique de Les Houches: “Nanoscale Radiative Heat Transfer ”
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Creation and protection of entanglement in systems out of thermal equilibrium
Auteur(s): Bellomo B., Antezza M.
(Article) Publié:
New Journal Of Physics, vol. 15 p.113052 (2013)
Texte intégral en Openaccess :
Ref HAL: hal-00909815_v1
DOI: 10.1088/1367-2630/15/11/113052
WoS: 000327550700007
Exporter : BibTex | endNote
39 Citations
Résumé: We investigate the creation of entanglement between two quantum emitters interacting with a realistic common stationary electromagnetic field out of thermal equilibrium. In the case of two qubits we show that the absence of equilibrium allows the generation of steady entangled states, which is inaccessible at thermal equilibrium and is realized without any further external action on the two qubits. We first give a simple physical interpretation of the phenomenon in a specific case and then we report a detailed investigation on the dependence of the entanglement dynamics on the various physical parameters involved. Sub- and super-radiant effects are discussed, and qualitative differences in the dynamics concerning both creation and protection of entanglement according to the initial two-qubit state are pointed out.
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Steady entanglement out of thermal equilibrium
Auteur(s): Bellomo B., Antezza M.
(Article) Publié:
Europhysics Letters (Epl), vol. 104 p.10006 (2013)
Texte intégral en Openaccess :
Ref HAL: hal-00880526_v1
DOI: 10.1209/0295-5075/104/10006
WoS: 000327448900005
Exporter : BibTex | endNote
31 Citations
Résumé: We study two two-level atomic quantum systems (qubits) placed close to a body held at a temperature different from that of the surrounding walls. While at thermal equilibrium the two-qubit dynamics is characterized by non-entangled steady thermal states, we show that the absence of thermal equilibrium may bring to the generation of entangled steady states. Remarkably, this entanglement emerges from the two-qubit dissipative dynamic itself, without any further external action on the two qubits, suggesting a new protocol to create and protect entanglement which is intrinsically robust to environmental effects.
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Photonic band gap in an imperfect atomic diamond lattice: penetration depth and effects of finite size and vacancies
Auteur(s): Antezza M., Castin Yvan
(Article) Publié:
-Physical Review A Atomic, Molecular, And Optical Physics [1990-2015], vol. 88 p.033844 (2013)
Texte intégral en Openaccess :
Ref HAL: hal-00818327_v1
Ref Arxiv: 1304.7188
DOI: 10.1103/PhysRevA.88.033844
WoS: 000324933100010
Ref. & Cit.: NASA ADS
Exporter : BibTex | endNote
24 Citations
Résumé: We study the effects of finite size and of vacancies on the photonic band gap recently predicted for an atomic diamond lattice. Close to a $J_g=0\to J_e=1$ atomic transition, and for atomic lattices containing up to $N\approx 3\times10^4$ atoms, we show how the density of states can be affected by both the shape of the system and the possible presence of a fraction of unoccupied lattice sites. We numerically predict and theoretically explain the presence of shape-induced border states and of vacancy-induced localized states appearing in the gap. We also investigate the penetration depth of the electromagnetic field which we compare to the case of an infinite system.
Commentaires: 14 pages, 7 figures
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Quantum systems in a stationary environment out of thermal equilibrium
Auteur(s): Bellomo B., Messina R., Felbacq D., Antezza M.
(Article) Publié:
-Physical Review A Atomic, Molecular, And Optical Physics [1990-2015], vol. 87 p.012101 (2013)
Texte intégral en Openaccess :
Ref HAL: hal-01241962_v1
DOI: 10.1103/PhysRevA.87.012101
WoS: 000312994700004
Exporter : BibTex | endNote
32 Citations
Résumé: We discuss how the thermalization of an elementary quantum system is modified when the system is placed in an environment out of thermal equilibrium. To this aim we provide a detailed investigation of the dynamics of an atomic system placed close to a body of arbitrary geometry and dielectric permittivity, whose temperature T_M is different from that of the surrounding walls T_W. A suitable master equation for the general case of an N-level atom is first derived and then specialized to the cases of a two- and three-level atom. Transition rates and steady states are explicitly expressed as a function of the scattering matrices of the body and become both qualitatively and quantitatively different from the case of radiation at thermal equilibrium. Out of equilibrium, the system steady state depends on the system-body distance, on the geometry of the body, and on the interplay of all such parameters with the body optical resonances. While a two-level atom tends toward a thermal state, this is not the case already in the presence of three atomic levels. This peculiar behavior can be exploited, for example, to invert the populations ordering and to provide an efficient cooling mechanism for the internal state of the quantum system.We finally provide numerical studies and asymptotic expressions when the body is a slab of finite thickness. Our predictions can be relevant for a wide class of experimental configurations out of thermal equilibrium involving different physical realizations of two- or three-level systems.
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Quantitative study of two- and three-dimensional strong localization of matter waves by atomic scatterers
Auteur(s): Antezza M.
(Séminaires)
Université Montpellier 2, L2C (Montpellier, FR), 2012-01-17 |