Uhlmann's geometric phase in presence of isotropic decoherence
2003 (English)In: Physical Review A. Atomic, Molecular, and Optical Physics, ISSN 1050-2947, E-ISSN 1094-1622, Vol. 67, no 3, 032110- p.Article in journal (Refereed) Published
Uhlmann's mixed state geometric phase [Rep. Math. Phys. 24, 229 (1986)] is analyzed in the case of a qubit affected by isotropic decoherence treated in the Markovian approximation. It is demonstrated that this phase decreases rapidly with increasing decoherence rate and that it is most fragile to weak decoherence for pure or nearly pure initial states. In the unitary case, we compare Uhlmann's geometric phase for mixed states with that occurring in standard Mach-Zehnder interferometry [Phys. Rev. Lett. 85, 2845 (2000)] and show that the latter is more robust to reduction in the length of the Bloch vector. We also describe how Uhlmann's geometric phase in the present case could in principle be realized experimentally.
Place, publisher, year, edition, pages
2003. Vol. 67, no 3, 032110- p.
Uhlmann holonomy, mixed quantum states, Lindblad equation
Research subject Physics
IdentifiersURN: urn:nbn:se:uu:diva-45733DOI: 10.1103/PhysRevA.67.032110ISI: 000181965900020OAI: oai:DiVA.org:uu-45733DiVA: diva2:73641
Also in Virtual Journal of Quantum Information, April issue 2003. 2007-02-062007-02-062011-10-05