  Using a unified approach of optical-mechanical analogy in a semiclassical
formula, we evaluate the effect of Chern-Simons modified gravity on the quantum
phase shift of de Broglie waves in neutron interferometry. The phase shift
calculated here reveals, in a single equation, a combination of effects coming
from Newtonian gravity, inertial forces, Schwarzschild and Chern-Simons
modified gravity. However the last two effects, though new, turn out to be too
tiny to be observed, and hence only of academic interest at present. The
approximations, wherever used, as well as the drawbacks of the non-dynamical
approach are clearly indicated.
