Comment on 'Correlative amplitude-operational phase entanglement embodied by the EPR-pair eigenstate vertical bar eta >'

摘要

In a recent paper in this journal Fan (Fan H 2002 J. Phys. A: Math. Gen. 35 1007) discards the possibility of using a genuine phase-difference operator to investigate number-phase entanglement because of the lack of unitarity of the Susskind-Glogower phase operators. However, Fan overlooked the existence of a bona fide unitary operator exponential of the phase difference. Here we find the amplitude-phase maximally entangled states as the simultaneous eigenstates of the total number And the phase-indifference operators. [References: 29]