Pointer states via Decoherence in a Quantum Measurement
We consider the interaction of a quantum system (spin-1/2) with a macroscopic quantum apparatus (harmonic oscillator) which in turn is coupled to a bath of harmonic oscillators. Exact solutions of the Markovian Master equation show that the reduced density matrix of the system-apparatus combine deco...
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ftdatacite:10.48550/arxiv.quant-ph/9909005 2023-05-15T18:32:41+02:00 Pointer states via Decoherence in a Quantum Measurement Venugopalan, Anu 1999 https://dx.doi.org/10.48550/arxiv.quant-ph/9909005 https://arxiv.org/abs/quant-ph/9909005 unknown arXiv https://dx.doi.org/10.1103/physreva.61.012102 Assumed arXiv.org perpetual, non-exclusive license to distribute this article for submissions made before January 2004 http://arxiv.org/licenses/assumed-1991-2003/ Quantum Physics quant-ph FOS Physical sciences article-journal Article ScholarlyArticle Text 1999 ftdatacite https://doi.org/10.48550/arxiv.quant-ph/9909005 https://doi.org/10.1103/physreva.61.012102 2022-04-01T17:18:34Z We consider the interaction of a quantum system (spin-1/2) with a macroscopic quantum apparatus (harmonic oscillator) which in turn is coupled to a bath of harmonic oscillators. Exact solutions of the Markovian Master equation show that the reduced density matrix of the system-apparatus combine decoheres to a statistical mixture where up and down spins eventually correlate with pointer states of the apparatus. For the zero temperature bath these pointer states turn out to be coherent states of the harmonic oscillator for arbitrary initial states of the apparatus. For a high temperature bath pointer states are Gaussian distributions (generalized coherent states). For both cases, the off-diagonal elements in spin-space decohere over a time scale which goes inversely as the square of the "separation" between the "pointers". Our exact results also demonstrate in an unambiguous way that the pointer states in this measurement model emerge independent of the initial state of the apparatus. : 9 pages, LaTex, communicated to Physical Review A Text The Pointers DataCite Metadata Store (German National Library of Science and Technology) |
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Quantum Physics quant-ph FOS Physical sciences |
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Quantum Physics quant-ph FOS Physical sciences Venugopalan, Anu Pointer states via Decoherence in a Quantum Measurement |
topic_facet |
Quantum Physics quant-ph FOS Physical sciences |
description |
We consider the interaction of a quantum system (spin-1/2) with a macroscopic quantum apparatus (harmonic oscillator) which in turn is coupled to a bath of harmonic oscillators. Exact solutions of the Markovian Master equation show that the reduced density matrix of the system-apparatus combine decoheres to a statistical mixture where up and down spins eventually correlate with pointer states of the apparatus. For the zero temperature bath these pointer states turn out to be coherent states of the harmonic oscillator for arbitrary initial states of the apparatus. For a high temperature bath pointer states are Gaussian distributions (generalized coherent states). For both cases, the off-diagonal elements in spin-space decohere over a time scale which goes inversely as the square of the "separation" between the "pointers". Our exact results also demonstrate in an unambiguous way that the pointer states in this measurement model emerge independent of the initial state of the apparatus. : 9 pages, LaTex, communicated to Physical Review A |
format |
Text |
author |
Venugopalan, Anu |
author_facet |
Venugopalan, Anu |
author_sort |
Venugopalan, Anu |
title |
Pointer states via Decoherence in a Quantum Measurement |
title_short |
Pointer states via Decoherence in a Quantum Measurement |
title_full |
Pointer states via Decoherence in a Quantum Measurement |
title_fullStr |
Pointer states via Decoherence in a Quantum Measurement |
title_full_unstemmed |
Pointer states via Decoherence in a Quantum Measurement |
title_sort |
pointer states via decoherence in a quantum measurement |
publisher |
arXiv |
publishDate |
1999 |
url |
https://dx.doi.org/10.48550/arxiv.quant-ph/9909005 https://arxiv.org/abs/quant-ph/9909005 |
genre |
The Pointers |
genre_facet |
The Pointers |
op_relation |
https://dx.doi.org/10.1103/physreva.61.012102 |
op_rights |
Assumed arXiv.org perpetual, non-exclusive license to distribute this article for submissions made before January 2004 http://arxiv.org/licenses/assumed-1991-2003/ |
op_doi |
https://doi.org/10.48550/arxiv.quant-ph/9909005 https://doi.org/10.1103/physreva.61.012102 |
_version_ |
1766216871554580480 |