116 research outputs found
Estimation of Poisson-Dirichlet Parameters with Monotone Missing Data
This article considers the estimation of the unknown numerical parameters and the density of the base measure in a Poisson-Dirichlet process prior with grouped monotone missing data. The numerical parameters are estimated by the method of maximum likelihood estimates and the density function is estimated by kernel method. A set of simulations was conducted, which shows that the estimates perform well
Experimental Realization of Asymmetric Phase-Covariant Quantum Cloning
While exact cloning of an unknown quantum state is prohibited by the
linearity of quantum mechanics, approximate cloning is possible and has been
used, e.g., to derive limits on the security of quantum communication
protocols. In the case of asymmetric cloning, the information from the input
state is distributed asymmetrically between the different output states. Here,
we consider asymmetric phase-covariant cloning, where the goal is to optimally
transfer the phase information from a single input qubit to different output
qubits. We construct an optimal quantum cloning machine for two qubits that
does not require ancilla qubits and implement it on an NMR quantum information
processor.Comment: 6 pages, 5 figure
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