Decoherence due to the sudden coupling of an impurity to a metal

Fuente: arXiv
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Autores principales: Picoli, Felipe D., Diniz, Gustavo, Oliveira, Luiz N.
Formato: Preprint
Publicado: 2026
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author Picoli, Felipe D.
Diniz, Gustavo
Oliveira, Luiz N.
author_facet Picoli, Felipe D.
Diniz, Gustavo
Oliveira, Luiz N.
contents We investigate the nonequilibrium dynamics and loss of coherence in a quantum impurity system using the spinless resonant level model subject to sudden quenches of the hybridization between the impurity and the metal. The survival probability (fidelity) and impurity occupation are analyzed as probes of the dephasing induced by particle-hole excitations. For finite systems, the loss of coherence loss is only apparent, as discrete spectra lead to quasi-periodic dynamics and revivals when phases realign. We show that a mixed linear-logarithmic discretization suppresses these finite-size artifacts by rendering excitation energies incommensurate, thereby reducing revivals. Starting from the exactly solvable two-level limit exhibiting coherent Rabi oscillations, we extend the analysis to large lattices, where damping and relaxation emerge. Combining analytical and numerical results, we provide a unified picture of the crossover from coherent oscillations to effectively irreversible decoherence.
format Preprint
id arxiv_https___arxiv_org_abs_2605_01612
institution arXiv
publishDate 2026
record_format arxiv
spellingShingle Decoherence due to the sudden coupling of an impurity to a metal
Picoli, Felipe D.
Diniz, Gustavo
Oliveira, Luiz N.
Mesoscale and Nanoscale Physics
Statistical Mechanics
Strongly Correlated Electrons
We investigate the nonequilibrium dynamics and loss of coherence in a quantum impurity system using the spinless resonant level model subject to sudden quenches of the hybridization between the impurity and the metal. The survival probability (fidelity) and impurity occupation are analyzed as probes of the dephasing induced by particle-hole excitations. For finite systems, the loss of coherence loss is only apparent, as discrete spectra lead to quasi-periodic dynamics and revivals when phases realign. We show that a mixed linear-logarithmic discretization suppresses these finite-size artifacts by rendering excitation energies incommensurate, thereby reducing revivals. Starting from the exactly solvable two-level limit exhibiting coherent Rabi oscillations, we extend the analysis to large lattices, where damping and relaxation emerge. Combining analytical and numerical results, we provide a unified picture of the crossover from coherent oscillations to effectively irreversible decoherence.
title Decoherence due to the sudden coupling of an impurity to a metal
topic Mesoscale and Nanoscale Physics
Statistical Mechanics
Strongly Correlated Electrons
url https://arxiv.org/abs/2605.01612