Decoherence due to an excited-state quantum phase transition in a two-level boson model
Citation
Description
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.
Abstract
Ministerio de Educación y Ciencia FIS2008-04189, FIS2006-12783-C03-01, FPA2006- 13807-C02-02, FPA2007-63074
Abstract
Comunidad de Madrid 200650M012
Abstract
Junta de Andalucía FQM160, FQM318, P05-FQM437, P07- FQM-02962
Additional details
- URL
- https://idus.us.es/handle//11441/84192
- URN
- urn:oai:idus.us.es:11441/84192
- Origin repository
- USE