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 ©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 18 abr 2025