Signal reflection, quantum non-locality, and delayed choice experiments

Quantum nonlocality which is conventionally invoked for describing a composite entangled system is shown here to be a possible important characteristic of a single quantum object. To this end, we analyze some interactions of a single photon released from Fabry Perot resonator with environment. The split photon state with oppositely moving parts is shown to obey quantum nonlocality despite the sharp edges truncating each part. Photon post release reflection from a plane mirror is considered. The changing shape of the form during reflection contains moving discontinuities in electric and magnetic components of the pulse. They originate from preexisting edges of the form and move together, first away from and then back to the mirror. At the end of the process, the pulse restores its original shape, with electric component reversed. Altogether, the process demonstrates conservation of moving discontinuities. The considered experimental setup may be used for some new versions of a delayed choice experiment, with various options for insertion of detectors and the respective time delays. In all cases, the delayed insertion does not have any retroactive effect on the process. Key words: Evolution operator, signaling, reflection, discontinuity, quantum nonlocality