Distance-based degrees of polarization for a quantum field
2005 (English)In: Physical Review A. Atomic, Molecular, and Optical Physics, ISSN 1050-2947, E-ISSN 1094-1622, Vol. 72, no 3Article in journal (Refereed) Published
It is well established that unpolarized light is invariant with respect to any SU(2) polarization transformation. This requirement fully characterizes the set of density matrices representing unpolarized states. We introduce the degree of polarization of a quantum state as its distance to the set of unpolarized states. We use two different candidates of distance, namely the Hilbert-Schmidt and the Bures metric, showing that they induce fundamentally different degrees of polarization. We apply these notions to relevant field states and we demonstrate that they avoid some of the problems arising with the classical definition.
Place, publisher, year, edition, pages
2005. Vol. 72, no 3
hilbert-schmidt distance, unpolarized radiation, entanglement measures, stokes parameters, relative entropy, phase-space, states, light, localization, information
IdentifiersURN: urn:nbn:se:kth:diva-15071DOI: 10.1103/PhysRevA.72.033813ISI: 000232228300163ScopusID: 2-s2.0-28844494988OAI: oai:DiVA.org:kth-15071DiVA: diva2:333112
QC 201005252010-08-052010-08-05Bibliographically approved