Experimental demonstration of a technique to generate arbitrary quantum superposition states of a harmonically bound spin-1/2 particle

The scheme of Law and Eberly for generation of arbitrary harmonic-oscillator states and its extension to arbitrary harmonic-oscillator/spin states was demonstrated. The method can be generalized to higher dimensions, to the generation of arbitrary density matrices of harmonic oscillators, to the creation of arbitrary motional observables such as the phase, and to the generation of arbitrary Zeeman state superpositions. With sufficient improvements in the fidelity of such operations, one can contemplate using additional motional modes of motion as information carriers in this scheme.