Local quanta, unitary inequivalence, and vacuum entanglement

Abstract

The elementary excitations of quantum elds are usually described by creation and anihilation operators that are sharp in momentum. Hence, the corresponding quanta are completely delocalized in space. Here we introduce localized quanta, analyze their physical properties and their unitarily inequivalence to standard Fock space quanta. In spite of being neatly local, they become entangled when excited from the global quantum vacuum even at spatially separated events.