# How does entanglement affect a photon's ability to interfere?

1. Jun 10, 2007

### AlexHT

Suppose a single entangled photon with wave function

$$|\phi > =$$$${1}\over{2 \sqrt{2}}$$$$( ((|H>+|V>)_A|H>_B)_C + ((|H>+|V>)_A|V>_B ))_D$$

If the signal in C is recombined with the signal in D, would the photon interfere with itself or not considering the entangled member is in opposite state?

More generally, how can I tell when a wave function is split in two with a beamsplitter, if when recombined, interference fringes will be seen at the detector?