ENTANGLEMENT OF AMPLITUDE AND OPTICAL PHASE INVOLVED IN THE EPR EIGENSTATE

By noticing that although single-mode Susskind–Glogower phase operator does not commute with photon number operator, two-mode nonlinear phase operator commutes with number-difference operator. We reveal that the common eigenstate <η| of two-particles' relative coordinate and total momentum involves the entanglement between phase and amplitude. We also reveal entanglement between number difference and amplitude inherent in the state |D,|η|>, where is a deductive state of |η>.