A state in a $d$-dimensional Hilbert space can be simulated by a state defined in a different dimension with high fidelity. We assess how faithfully such an approximated state can perform quantum protocols using an example of the squeezed coherent superposition state, which was recently experimentally generated.

• Received 20 May 2008

DOI:https://doi.org/10.1103/PhysRevA.78.022309