Universality and Optimality of Programmable Quantum Processors

Mário Ziman, Vladimír Bužek
2006 Acta Physica Hungarica A: Heavy Ion Physics  
We analyze and compare the optimality of approximate and probabilistic universal programmable quantum processors. We define several characteristics how to quantify the optimality and we study in detail performance of three types of programmable quantum processors based on (1) the C-NOT gate, (2) the SWAP operation, and (3) the model of the quantum information distributor - the QID processor. We show under which conditions the measurement assisted QID processor is optimal. We also investigate
more » ... imality of the so-called U-processors and we also compare the optimal approximative implementation of U(1) qubit rotations with the known probabilistic implementation as introduced by Vidal, Masanes and Cirac [ Phys. Rev. Lett. 88, 047905 (2002)].
doi:10.1556/aph.26.2006.3-4.8 fatcat:ntnf4erezndt3elhba23r4kwem