RT Journal Article T1 Decoherence due to an excited-state quantum phase transition in a two-level boson model A1 Relaño Pérez, Armando A1 Pérez Fernández, P. A1 Arias, J. M. A1 Dukelsky, J. A1 García Ramos, J. E. AB The decoherence induced on a single qubit by its interaction with the environment is studied. The environment is modeled as a scalar two-level boson system that can go through either first-order or continuous-excited-state quantum phase transitions, depending on the values of the control parameters. A mean-field method based on the Tamm-Damkoff approximation is worked out in order to understand the observed behavior of the decoherence. Only the continuous-excited-state phase transition produces a noticeable effect in the decoherence of the qubit. This is maximal when the system-environment coupling brings the environment to the critical point for the continuous phase transition. In this situation, the decoherence factor (or the fidelity) goes to zero with a finite-size scaling power law. PB American Physical Society SN 1050-2947 YR 2009 FD 2009-09 LK https://hdl.handle.net/20.500.14352/44423 UL https://hdl.handle.net/20.500.14352/44423 LA eng NO [1] W. H. Zurek, Rev. Mod. Phys. 75, 715 (2003).[2] M. Schlosshauer, Rev. Mod. Phys. 76, 1267 (2005).[3] F. M. Cucchietti, S. Fernández Vidal, and J. P. Paz, Phys. Rev. A 75, 032337 (2007).[4] C. Cormick and J. P. Paz, Phys. Rev. A 77, 022317 (2008).[5] D. Rossini, T. Calarco, V. Giovannetti, S. Montangero, and R. Fazio, Phys. Rev. A 75, 032333 (2007).[6] L. C. Wang, H. T. Cui, and X.-X. Yi, Phys. Lett. A 372, 1387 (2008).[7] S. Camalet and R. Chitra, Phys. Rev. Lett. 99, 267202 (2007).[8] Z.-G. Yuan, P. Zhang, and S.-S. Li, Phys. Rev. A 75, 012102 (2007).[9] A. Relaño, J. M. Arias, J. Dukelsky, J. E. García Ramos, P. Pérez Fernández, Phys. Rev. A 78, 060102 (R) (2008).[10] P. Cejnar, S. Heinze, and M. Macek, Phys. Rev. Lett. 99, 100601 (2007).[11] P. Cejnar and J. Jolie, Prog. Part. Nucl. Phys. 62, 210 (2009).[12] W. D. Heiss, F. G. Scholtz, and H. B. Geyer, J. Phys. A 38, 1843 (2005); F. Leyvraz and W. D. Heiss, Phys. Rev. Lett. 95, 050402 (2005); W. D. Heiss, J. Phys. A 39, 10081 (2006).[13] S. Heinze, P. Cejnar, J. Jolie, and M. Macek, Phys. Rev. C 73, 014306 (2006); M. Macek, P. Cejnar, J. Jolie, and S. Heinze, ibid. 73, 014307 (2006); P. Cejnar, M. Macek, S. Heinze, J. Jolie, and J. Dobes, J. Phys. A 39, L515 (2006).[14] M. A. Caprio, P. Cejnar, and F. Iachello, Ann. Phys. 323, 1106 (2008).[15] P. Cejnar and P. Stránský, Phys. Rev. E 78, 031130 (2008).[16] J. Vidal, J. M. Arias, J. Dukelsky, and J. E. García Ramos, Phys. Rev. C 73, 054305 (2006); J. M. Arias, J. Dukelsky, J. E. García Ramos, and J. Vidal, ibid. 75, 014301 (2007). NO ©2009 The American Physical Society. This work has been partially supported by the Spanish Ministerio de Educacion y Ciencia and by the European regional development fund (FEDER) under Projects No. FIS2008-04189, No. FIS2006-12783-C03-01, No. FPA2006-13807-C02-02, and No. FPA2007-63074, by CPAN-Ingenio, by Comunidad de Madrid under Project No. 200650M012, CSIC, and by Junta de Analucia a under Projects No. FQM160, No. FQM318, No. P05-FQM437, and No. P07-FQM-02962. A. R. is supported by the Spanish program "Juan de la Cierva" and P. P- F. is supported by a FPU grant of the Spanish Ministerio de Educacion y Ciencia. NO Ministerio de Educación y Ciencia NO European regional development fund (FEDER) NO Comunidad de Madrid NO Junta de Andalucia NO Spanish program "Juan de la Cierva" NO CPAN-Ingenio NO CSIC DS Docta Complutense RD 6 may 2024