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Conditional SIC-POVMs

Research paper by D. Petz, L. Ruppert, A. Szanto

Indexed on: 26 Feb '12Published on: 26 Feb '12Published in: Quantum Physics



Abstract

In this paper we examine a generalization of the symmetric informationally complete POVMs. SIC-POVMs are the optimal measurements for full quantum tomography, but if some parameters of the density matrix are known, then the optimal SIC POVM should be orthogonal to a subspace. This gives the concept of the conditional SIC-POVM. The existence is not known in general, but we give a result in the special cases when the diagonal is known of the density matrix.