# OPTIMAL CLONING OF PURE STATES

@article{Werner1998OPTIMALCO, title={OPTIMAL CLONING OF PURE STATES}, author={Reinhard F. Werner}, journal={Physical Review A}, year={1998}, volume={58}, pages={1827-1832} }

We construct the unique optimal quantum device for turning a finite number of d-level quantum systems in the same unknown pure state \sigma into M systems of the same kind, in an approximation of the M-fold tensor product of the state \sigma.

## 36 Citations

Bounds on the efficiency of cloning for two-state quantum systems

- Physics
- 2000

We analyse the efficiency of quantum cloning for qubits. We investigate, in particular, the role played by the form of allowed input states and show how the fidelity of cloning changes by restricting…

Quantum cloning machine of a state in a belt of Bloch sphere

- Physics
- 2009

AbstractWe analyze the problem of approximate quantum cloning when the
quantum state is between two latitudes on the Bloch’s sphere. We
present an analytical formula for the optimized 1-to-2 cloning.…

A quantum network for implementation of the optimal quantum cloning

- Physics
- 2009

This paper presents a quantum network to implement the optimal 1 → 2 quantum cloning in 2 dimensions, including the optimal asymmetric universal, the optimal symmetric phase-covariant, and the…

Optimal cloning for two pairs of orthogonal states

- Mathematics
- 2001

We study the optimal cloning transformation for two pairs of orthogonal states of two-dimensional quantum systems, and derive the corresponding optimal fidelities.

On the Entanglement Structure in Quantum Cloning

- Physics
- 2002

We study the entanglement properties of the output state of a universal cloning machine. We analyse in particular bipartite and tripartite entanglement of the clones, and discuss the “classical…

Quantum Cloning Optimal for Joint Measurements

- Mathematics
- 2002

We show that universally covariant cloning is not optimal for achieving joint measurements of noncommuting observables with minimum added noise. For such a purpose a cloning transformation that is…

Optimal cloning of pure states, testing single clones

- Mathematics
- 1999

We consider quantum devices for turning a finite number N of d-level quantum systems in the same unknown pure state σ into M>N systems of the same kind, in an approximation of the M-fold tensor…

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