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...
| Autores: | , , |
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| Formato: | artículo |
| Estado: | Versión publicada |
| Fecha de publicación: | 2013 |
| País: | Argentina |
| Recursos: | Consejo Nacional de Investigaciones Científicas y Técnicas |
| Repositorio: | CONICET Digital (CONICET) |
| Idioma: | inglés |
| OAI Identifier: | oai:ri.conicet.gov.ar:11336/25869 |
| Acesso em linha: | http://hdl.handle.net/11336/25869 |
| Access Level: | acceso abierto |
| Palavra-chave: | Decoherence Loschmidt Echo Spin Boson Model Coherent States https://purl.org/becyt/ford/1.3 https://purl.org/becyt/ford/1 |
| Resumo: | 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. |
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