arXiv:quant-ph/0310013 · Journal of Optics B Quantum and Semiclassical Optics
Informationally complete measurements and group representation
Giacomo Mauro D’Ariano, Paolo Perinotti, Massimiliano Federico Sacchi
Abstract
Informationally complete measurements on a quantum system allow one to estimate the expectation value of any arbitrary operator by just averaging functions of the experimental outcomes. We show that such kinds of measurement can be achieved through positive-operator valued measures (POVMs) related to unitary irreducible representations of a group on the Hilbert space of the system. With the help of frame theory we provide a constructive way to evaluate the data-processing function for arbitrary operators.