Quantal phase for nonmaximally entangled photons
Björn Hessmo, Erik Sjöqvist · Physical Review A · 2000
We calculate the Pancharatnam phase difference obtained when entangled two-photon states interfere. This phase depends nontrivially on the degree of entanglement between the photons forming the two-photon state. We outline an experiment where the entanglement dependence of the two-photon phase may be studied interferometrically. Also we propose how a cyclic version of this phase may be useful for implementing an efficient quantum gate.