Sub-femtosecond dynamics and dissociation of C-H bonds in the condensed phase: Effects of entangled protonic states

According to quantum theory, adjacent particles of condensed systems may ex hibit quantum interference and/or correlation phenomena being caused by int erparticle interactions. Here we present, for the first time, direct experi mental evidence for short-lived quantum entanglement of protons of C-H bond s. Neutron Compton scattering results from solid polystyrene reveal that, i n the sub-femtosecond time scale, the measured cross-section density of the protons is "anomalously" reduced by ca. 20%. A first-principles theoretica l treatment of this effect is given, which is based on the well-known van H ove formalism, and also takes explicitly into account quantum entanglement of protonic states and its decoherence. Besides its fundamental physical ch aracter, the effect may have considerable chemical and biological applicati ons, and also be of technical importance, e.g., for the engineering of some neutron moderators. (C) 2000 American Institute of Physics. [S0021-9606(00 )00431-1].