Fragility of superposition states evaluated by the Loschmidt echo

We consider the degradation of the dynamics of a Gaussian wave packet in a harmonic oscillator under the presence of an environment. This last is given by a single nondegenerate two-level system. We analyze how the binary degree of freedom perturbs the free evolution of the wave packet producing dec...

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Publicado: 2013
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Acceso en línea:https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_10502947_v88_n3_p_Bendersky
http://hdl.handle.net/20.500.12110/paper_10502947_v88_n3_p_Bendersky
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spelling paper:paper_10502947_v88_n3_p_Bendersky2023-06-08T16:02:46Z Fragility of superposition states evaluated by the Loschmidt echo Coherent superpositions Degree of freedom Energy separations Gaussian Wave Packets Harmonic oscillators Quantum evolution Superposition state Two-level system Physics Mathematical models We consider the degradation of the dynamics of a Gaussian wave packet in a harmonic oscillator under the presence of an environment. This last is given by a single nondegenerate two-level system. We analyze how the binary degree of freedom perturbs the free evolution of the wave packet producing decoherence, which is quantified by the Loschmidt echo. This magnitude measures the reversibility of a perturbed quantum evolution. In particular, we use it here to study the relative "fragility" of coherent superpositions (cat states) with respect to incoherent ones. This fragility or sensitivity turns out to increase exponentially with the energy separation of the two components of the superposition. © 2013 American Physical Society. 2013 https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_10502947_v88_n3_p_Bendersky http://hdl.handle.net/20.500.12110/paper_10502947_v88_n3_p_Bendersky
institution Universidad de Buenos Aires
institution_str I-28
repository_str R-134
collection Biblioteca Digital - Facultad de Ciencias Exactas y Naturales (UBA)
topic Coherent superpositions
Degree of freedom
Energy separations
Gaussian Wave Packets
Harmonic oscillators
Quantum evolution
Superposition state
Two-level system
Physics
Mathematical models
spellingShingle Coherent superpositions
Degree of freedom
Energy separations
Gaussian Wave Packets
Harmonic oscillators
Quantum evolution
Superposition state
Two-level system
Physics
Mathematical models
Fragility of superposition states evaluated by the Loschmidt echo
topic_facet Coherent superpositions
Degree of freedom
Energy separations
Gaussian Wave Packets
Harmonic oscillators
Quantum evolution
Superposition state
Two-level system
Physics
Mathematical models
description We consider the degradation of the dynamics of a Gaussian wave packet in a harmonic oscillator under the presence of an environment. This last is given by a single nondegenerate two-level system. We analyze how the binary degree of freedom perturbs the free evolution of the wave packet producing decoherence, which is quantified by the Loschmidt echo. This magnitude measures the reversibility of a perturbed quantum evolution. In particular, we use it here to study the relative "fragility" of coherent superpositions (cat states) with respect to incoherent ones. This fragility or sensitivity turns out to increase exponentially with the energy separation of the two components of the superposition. © 2013 American Physical Society.
title Fragility of superposition states evaluated by the Loschmidt echo
title_short Fragility of superposition states evaluated by the Loschmidt echo
title_full Fragility of superposition states evaluated by the Loschmidt echo
title_fullStr Fragility of superposition states evaluated by the Loschmidt echo
title_full_unstemmed Fragility of superposition states evaluated by the Loschmidt echo
title_sort fragility of superposition states evaluated by the loschmidt echo
publishDate 2013
url https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_10502947_v88_n3_p_Bendersky
http://hdl.handle.net/20.500.12110/paper_10502947_v88_n3_p_Bendersky
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