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Local-Field Corrections as a Regularization Method for the Spin-Boson Model

The decoherence rate of a ‘central spin’ in a bosonic bath of magnetic fluctuations is computed using the spin-boson model. The magnetic fluctuations are treated in a fully quantum mechanical way by using the macroscopic quantum electrodynamics formalism and are expressed in terms of the classical e...

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Autor principal: Crosse, J. A.
Formato: Online Artículo Texto
Lenguaje:English
Publicado: Nature Publishing Group UK 2019
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6435645/
https://www.ncbi.nlm.nih.gov/pubmed/30914667
http://dx.doi.org/10.1038/s41598-019-41303-0
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author Crosse, J. A.
author_facet Crosse, J. A.
author_sort Crosse, J. A.
collection PubMed
description The decoherence rate of a ‘central spin’ in a bosonic bath of magnetic fluctuations is computed using the spin-boson model. The magnetic fluctuations are treated in a fully quantum mechanical way by using the macroscopic quantum electrodynamics formalism and are expressed in terms of the classical electromagnetic Green’s function of the system. The resulting frequency integral formally diverges but it can be regularized by applying real-cavity, local-field corrections to the location of the ‘central spin’. This results in a cut-off function in terms of the magnetic permeability of the background material that leads to convergence at both high and low frequencies. This cut-off function appears naturally from the formalism and thus removes the need to rely on ad-hoc arguments to justify the form of the cut-off function. Furthermore, the magnetic permeability and the nature of interactions in quantum electrodynamics illuminate the connection between the two main models of ‘central spin’ decoherence, the spin-boson model and the spin-bath model, demonstrating how the two very different models are able to correctly model the same underlying physics.
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spelling pubmed-64356452019-04-02 Local-Field Corrections as a Regularization Method for the Spin-Boson Model Crosse, J. A. Sci Rep Article The decoherence rate of a ‘central spin’ in a bosonic bath of magnetic fluctuations is computed using the spin-boson model. The magnetic fluctuations are treated in a fully quantum mechanical way by using the macroscopic quantum electrodynamics formalism and are expressed in terms of the classical electromagnetic Green’s function of the system. The resulting frequency integral formally diverges but it can be regularized by applying real-cavity, local-field corrections to the location of the ‘central spin’. This results in a cut-off function in terms of the magnetic permeability of the background material that leads to convergence at both high and low frequencies. This cut-off function appears naturally from the formalism and thus removes the need to rely on ad-hoc arguments to justify the form of the cut-off function. Furthermore, the magnetic permeability and the nature of interactions in quantum electrodynamics illuminate the connection between the two main models of ‘central spin’ decoherence, the spin-boson model and the spin-bath model, demonstrating how the two very different models are able to correctly model the same underlying physics. Nature Publishing Group UK 2019-03-26 /pmc/articles/PMC6435645/ /pubmed/30914667 http://dx.doi.org/10.1038/s41598-019-41303-0 Text en © The Author(s) 2019 Open Access This article is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made. The images or other third party material in this article are included in the article’s Creative Commons license, unless indicated otherwise in a credit line to the material. If material is not included in the article’s Creative Commons license and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this license, visit http://creativecommons.org/licenses/by/4.0/.
spellingShingle Article
Crosse, J. A.
Local-Field Corrections as a Regularization Method for the Spin-Boson Model
title Local-Field Corrections as a Regularization Method for the Spin-Boson Model
title_full Local-Field Corrections as a Regularization Method for the Spin-Boson Model
title_fullStr Local-Field Corrections as a Regularization Method for the Spin-Boson Model
title_full_unstemmed Local-Field Corrections as a Regularization Method for the Spin-Boson Model
title_short Local-Field Corrections as a Regularization Method for the Spin-Boson Model
title_sort local-field corrections as a regularization method for the spin-boson model
topic Article
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6435645/
https://www.ncbi.nlm.nih.gov/pubmed/30914667
http://dx.doi.org/10.1038/s41598-019-41303-0
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