Abstract. After a penetrating analysis of the known number–phase commutative relations we find that the common eigenvector |η of two particles' relative coordinate and total momentum also embodies the entanglement with respect to the correlative amplitude–operational phase. Based on the fact that the number-difference operator is the canonical conjugate to the Noh–Fougères–Mandel operational phase operator, the corresponding entanglement is also briefly discussed.

PACS numbers: 03.65.Ud, 03.67.−a

Print publication: Issue 4 (1 February 2002)
Received 20 August 2001, in final form 20 November 2001
Published 18 January 2002