Three Plate Interferometry in Phase-Space

Abstract

For many years it has been known from classical optics that the coherence properties manifest themselves in a spatial intensity variation for phase shifts smaller than the coherence length and in a spectral variation for large phase shifts

It is generally known that coupling in phase-space is very effectively described in terms of the Wigner function [5, 35], which represents a quasiprobability distribution routinely used in quantum optics [2,6]. The formalism of Wigner function representation was introduced to visualize the behavior of various quantum systems that exhibit typical quantum optical phenomena. Although it cannot be interpreted as a probability function because of its partially negative values (see Part I), it is useful for the interpretation of various quantum effects. Neutron optics deals with massive particles, but can be formulated in quantum-optical terms also including the Wigner function formalism [24]. When the spatial phase shift, applied inside the interferometer to one coherent beam, becomes larger than the coherence length, spatially separated coherent Schrödinger-cat-like states are produced, which exhibit typical non-classical features and are notoriously fragile against any dissipations and fluctuations existing in any experimental arrangement, as will be discussed in later sections.