A comparative study of the optical and circuit representation of the unambiguous quantum state discriminator

We propose a quantum circuit implementation of the unambiguous quantum state discriminator. The circuit is made entirely of standard logical quantum gates, and provides an optimal implementation of the Positive Operator Valued Measurement (POVM) for the unambiguous discrimination of quantum states. We also propose an actual experimental setup of this device using the vibrational degrees of freedom of one- or two-dimensional ion traps. We compare this implementation to the one that has been used exclusively so far in experiments, which is based on single-photon interferometry, and discuss their relative advantages.