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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todo:paper_10980121_v80_n21_p_Winograd2023-10-03T16:06:13Z Weak-coupling study of decoherence of a qubit in disordered magnetic environments Winograd, E.A. Rozenberg, M.J. Chitra, R. 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. JOUR info:eu-repo/semantics/openAccess http://creativecommons.org/licenses/by/2.5/ar http://hdl.handle.net/20.500.12110/paper_10980121_v80_n21_p_Winograd |
| institution |
Universidad de Buenos Aires |
| institution_str |
I-28 |
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R-134 |
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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. |
| format |
JOUR |
| author |
Winograd, E.A. Rozenberg, M.J. Chitra, R. |
| spellingShingle |
Winograd, E.A. Rozenberg, M.J. Chitra, R. Weak-coupling study of decoherence of a qubit in disordered magnetic environments |
| author_facet |
Winograd, E.A. Rozenberg, M.J. Chitra, R. |
| author_sort |
Winograd, E.A. |
| 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 |
| url |
http://hdl.handle.net/20.500.12110/paper_10980121_v80_n21_p_Winograd |
| work_keys_str_mv |
AT winogradea weakcouplingstudyofdecoherenceofaqubitindisorderedmagneticenvironments AT rozenbergmj weakcouplingstudyofdecoherenceofaqubitindisorderedmagneticenvironments AT chitrar weakcouplingstudyofdecoherenceofaqubitindisorderedmagneticenvironments |
| _version_ |
1807316435079266304 |