Process optimized quantum cloners via semidefinite programming

TL;DR

This paper uses semidefinite programming to design optimized symmetric quantum cloners for qubits, improving fidelity by numerically approximating nonphysical maps, and analyzing their properties.

Contribution

It introduces a numerical semidefinite programming approach to design and analyze symmetric quantum cloners, a novel method in quantum information processing.

Findings

Optimized 1 to 2 qubit cloners with high fidelity

Numerical method approximates nonphysical maps effectively

Analysis of properties of the designed cloners

Abstract

We apply semidefinite programming for designing 1 to 2 symmetric qubit quantum cloners. These are optimized for the average fidelity of their joint output state with respect to a product of multiple originals. We design 1 to 2 quantum bit cloners using the numerical method for finding completely positive maps approximating a nonphysical one optimally. We discuss the properties of the so-designed cloners.