Weak-coupling study of decoherence of a qubit in disordered magnetic environments

We study the decoherence of a qubit weakly coupled to frustrated spin baths. We focus on spin baths described by the classical Ising spin glass and the quantum random transverse Ising model which are known to have complex thermodynamic phase diagrams as a function of an external magnetic field and t...

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Autor principal: Rozenberg, Marcelo Javier
Publicado: 2009
Acceso en línea:https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_10980121_v80_n21_p_Winograd
http://hdl.handle.net/20.500.12110/paper_10980121_v80_n21_p_Winograd
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Biblioteca Digital - Facultad de Ciencias Exactas y Naturales (UBA) de Universidad de Buenos Aires
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spelling paper:paper_10980121_v80_n21_p_Winograd2023-06-08T16:07:45Z Weak-coupling study of decoherence of a qubit in disordered magnetic environments Rozenberg, Marcelo Javier We study the decoherence of a qubit weakly coupled to frustrated spin baths. We focus on spin baths described by the classical Ising spin glass and the quantum random transverse Ising model which are known to have complex thermodynamic phase diagrams as a function of an external magnetic field and temperature. Using a combination of numerical and analytical methods, we show that for baths initially in thermal equilibrium, the resulting decoherence is highly sensitive to the nature of the coupling to the environment and is qualitatively different in different parts of the phase diagram. We find an unexpected strong non-Markovian decay of the coherence when the random transverse Ising model bath is prepared in an initial state characterized by a finite temperature paramagnet. This is contrary to the usual case of exponential decay (Markovian) expected for spin baths in finite temperature paramagnetic phases, thereby illustrating the importance of the underlying nontrivial dynamics of interacting quantum spinbaths. © 2009 The American Physical Society. Fil:Rozenberg, M.J. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina. 2009 https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_10980121_v80_n21_p_Winograd http://hdl.handle.net/20.500.12110/paper_10980121_v80_n21_p_Winograd
institution Universidad de Buenos Aires
institution_str I-28
repository_str R-134
collection Biblioteca Digital - Facultad de Ciencias Exactas y Naturales (UBA)
description We study the decoherence of a qubit weakly coupled to frustrated spin baths. We focus on spin baths described by the classical Ising spin glass and the quantum random transverse Ising model which are known to have complex thermodynamic phase diagrams as a function of an external magnetic field and temperature. Using a combination of numerical and analytical methods, we show that for baths initially in thermal equilibrium, the resulting decoherence is highly sensitive to the nature of the coupling to the environment and is qualitatively different in different parts of the phase diagram. We find an unexpected strong non-Markovian decay of the coherence when the random transverse Ising model bath is prepared in an initial state characterized by a finite temperature paramagnet. This is contrary to the usual case of exponential decay (Markovian) expected for spin baths in finite temperature paramagnetic phases, thereby illustrating the importance of the underlying nontrivial dynamics of interacting quantum spinbaths. © 2009 The American Physical Society.
author Rozenberg, Marcelo Javier
spellingShingle Rozenberg, Marcelo Javier
Weak-coupling study of decoherence of a qubit in disordered magnetic environments
author_facet Rozenberg, Marcelo Javier
author_sort Rozenberg, Marcelo Javier
title Weak-coupling study of decoherence of a qubit in disordered magnetic environments
title_short Weak-coupling study of decoherence of a qubit in disordered magnetic environments
title_full Weak-coupling study of decoherence of a qubit in disordered magnetic environments
title_fullStr Weak-coupling study of decoherence of a qubit in disordered magnetic environments
title_full_unstemmed Weak-coupling study of decoherence of a qubit in disordered magnetic environments
title_sort weak-coupling study of decoherence of a qubit in disordered magnetic environments
publishDate 2009
url https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_10980121_v80_n21_p_Winograd
http://hdl.handle.net/20.500.12110/paper_10980121_v80_n21_p_Winograd
work_keys_str_mv AT rozenbergmarcelojavier weakcouplingstudyofdecoherenceofaqubitindisorderedmagneticenvironments
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