  We present a gravitationally rigorous and clear answer, in the negative, to
the question whether gravimetry with atom interferometers is equivalent to the
the measurement of the relative gravitational time dilation of two clocks
separated in space. Though matter and light waves, quantum states and
oscillator clocks are quantum synonymous through the Planck-Einstein-de Broglie
relations and the equivalence principle, there are crucial differences in the
context of tests of gravitation theories.
