  We propose a new approach to study the transition between different
topological states, based on the assessment of the vibrational resonances in
infrared spectra. We consider the Haldane and Kane-Mele models finding that
Born effective charges are nearly quantized, with a discontinuous jump
concomitant with the topological phase transition. In particular, Born
effective charges display a finite value in the trivial phase and a null one in
the nontrivial one. This is rooted in the connection between Born effective
charges and electronic Berry curvature at the band edges. Finally, at the
topological phase transition of the Haldane model, we also observe a nearly
quantized jump of the chiral splitting of the zone-center phonon frequencies,
induced by time-reversal symmetry breaking.
