222 citations · 2.2k across the 95 of their papers we have counts for
4 papers · 1 filter
Nonuniqueness of phase retrieval for three fractional Fourier transforms
Claudio Carmeli, Teiko Heinosaari, Jussi Schultz +1
We prove that, regardless of the choice of the angles , three fractional Fourier transforms , and do not solve the phase retrieval problem…
Extending quantum operations
Teiko Heinosaari, Maria A. Jivulescu, David Reeb +1
For a given set of input-output pairs of quantum states or observables, we ask the question whether there exists a physically implementable transformation that maps each of the inp…
Covariant quantum instruments
Claudio Carmeli, Teiko Heinosaari, Alessandro Toigo
The structure of covariant instruments is studied and a general structure theorem is derived. A detailed characterization is given to covariant instruments in the case of an irredu…
Extremal covariant positive operator valued measures: the case of a compact symmetry group
Claudio Carmeli, Teiko Heinosaari, Juha-Pekka Pellonpää +1
Given a unitary representation U of a compact group G and a transitive G-space , we characterize the extremal elements of the convex set of all U-covariant positive operator val…