Approximate Quantum Cloning with Nuclear Magnetic Resonance

Here we describe a nuclear magnetic resonance (NMR) experiment that uses a three qubit NMR device to implement the one-to-two approximate quantum cloning network of Bužek et al. [Phys. Rev. A 56, 3446 (1997)]. As expected the experimental results indicate that the network clones all input states with similar fidelities, but as a result of decoherence and incoherent evolution arising from B₁ inhomogeneity the total fidelity achieved does not exceed the measurement bound.