  When gravity is quantized, there inevitably exist quantum gravitational
vacuum fluctuations which induce quadrupole moments in gravitationally
polarizable objects and produce a quantum correction to the classical Newtonian
interaction between them. Here, based upon linearized quantum gravity and the
leading-order perturbation theory, we study, from a quantum field-theoretic
prospect, this quantum correction between a pair of gravitationally polarizable
objects treated as two-level harmonic oscillators. We find that the interaction
potential behaves like $r^{-11}$ in the retarded regime and $r^{-10}$ in the
near regime. Our result agrees with what was recently obtained in different
approaches. Our study seems to indicate that linearized quantum gravity is
robust in dealing with quantum gravitational effects at low energies.
