Phase operators and a special kind of transformation in the Hilbert space of a two-mode boson
Sixia Yu · Physical Review A · 1997
A special kind of unitary transformation capable of changing the degrees of freedom of a quantum system, a super quantum coordinate transformation, is introduced. Two such transformations in the Hilbert space of a two-mode boson are investigated in detail. Under one transformation, this two-mode bosonic Hilbert space is transformed to a Hilbert space of a two-mode boson plus a single-mode fermion; under the other transformation, it is transformed to a Hilbert space of a single-mode boson. Their applications to phase operators and the phase difference operator are discussed.