The development of high sensitivity and high accuracy atom interferometers
requires new theoretical tools for their modelization: in this article we e
mphasize specifically a generalized Fresnel-Kirchhoff formula for atom opti
cs in the form of ABCD matrices and covariant wave equations in the form of
a Dirac equation for atom optics in the presence of gravito-inertial field
s. As examples, we derive the phase shift for the atom gravimeter and the o
utput of an atom laser. Some of the physics of the beam splitters is descri
bed. We present a second-quantized field theory of massive spin one-half pa
rticles or antiparticles in the presence of a weak gravitational field trea
ted as a spin two external field in a Rat Minkowski background. This theory
is used to calculate and discuss relativistic phase shifts in the context
of matter-wave interferometry (especially atom or antiatom interferometry).
In this way, many effects are introduced in a unified relativistic framewo
rk, including spin-gravitation terms: gravitational red shift, Thomas prece
ssion, Sagnac effect, spin-rotation effect, orbital and spin Lense-Thirring
effects, de Sitter geodetic precession and finally the effect of gravitati
onal waves. (C) 2001 Academie des sciences/Editions scientifiques et medica
les Elsevier SAS.