Fault-tolerant architectures for superconducting qubits
David P. DiVincenzo
Nobel Symposium: Qubits for Future Quantum Information 2009
We establish the best possible approximation to a perfect quantum cloning machine that produces two clones out of a single input. We analyze both universal and state-dependent cloners. The maximal fidelity of cloning is shown to be 5/6 for universal cloners. It can be achieved either by a special unitary evolution or by a teleportation scheme. We construct the optimal state-dependent cloners operating on any prescribed two nonorthogonal states and discuss their fidelities and the use of auxiliary physical resources in the process of cloning. The optimal universal cloners permit us to derive an upper bound on the quantum capacity of the depolarizing quantum channel. © 1998 The American Physical Society.
David P. DiVincenzo
Nobel Symposium: Qubits for Future Quantum Information 2009
Daniel Loss, David P. DiVincenzo
Physical Review A - AMO
Charles H. Bennett, David P. DiVincenzo, et al.
Physical Review Letters
David P. DiVincenzo, William Krakow, et al.
Journal of Non-Crystalline Solids