総説・解説等

A study was conducted to bridge discrete and continuous variables (CV) in quantum information. The generated states were best understood in terms of continuous variables when looked at individually. They consisted of contributions from a range of different photon number states and occupied a larger space than the two-dimensional qubit space. It was demonstrated they were reduced to the same squeezed vacuum or squeezed photon superposition space. It was observed the qubit state was conveniently visualized on a Poincaré sphere with the two basis states represented on the north and south poles, while squeezed states were represented by their continuous distributions in a phase space of the two conjugate variables.