Nonlinear phase shifts at the two-photon level can be greatly enhanced by a cooperative effect involving pairs of atoms, which can give a phase shift proportional to the square of the number of atoms in a medium. This is a nonlocal quantum effect that does not exist for classical states of light. Cooperative effects of this kind may have practical applications in quantum computing.
No takes yet. Share an insight, caveat, or question.
J. D. Franson (1997) studied this question.
Synapse has enriched 5 closely related papers on similar clinical questions. Consider them for comparative context: