Environmentally induced corrections to the geometric phase in a two-level system

FERNANDO C. LOMBARDO & PAULA I. VILLAR

International Journal of Quantum Information

World Scientific Publishing Company

Año: 2008 vol. 6 p. 707 - 713

We calculate the geometric phase for different open systems (spin-boson and spin-spin models). Even though there have been many assumptions about the time scale at which the geometric phase can be measured, there has been no reported observation of geometric phases for mixed states under nonunitary evolution yet. We study not only how they are corrected by the presence of the different type of environments but also discuss the appearence of decoherence effects that should be taken into account when planning experimental setups to study the geometric phase in the nonunitary regime, particularly important for the application of fault-tolerant quantum computation.