Quantum Information Processing with Trapped Ca+ Ions - Multi-particle entanglement and quantum metrology –
R. Blatt · International Conference on Quantum Information · 2007
Strings of trapped Ca+ ions serve as a quantum register to produce and characterize multipartite quantum states. Using a decoherence-free subspace with specifically designed entangled states we demonstrate precision spectroscopy of a pair of trapped Ca+ ions; we obtain the electric quadrupole moment, which is of use for frequency standard applications.