  To elucidate the superconductor to metal transition at the end of
superconducting dome, the overdoped regime has stepped onto the center stage of
cuprate research recently. Here, we use scanning tunneling microscopy to
investigate the atomic-scale electronic structure of overdoped trilayer Bi-2223
and bilayer Bi-2212 cuprates. At low energies the spectroscopic maps are well
described by dispersive quasiparticle interference patterns. However, as the
bias increases to the superconducting coherence peak energy, a virtually
non-dispersive pattern with sqrt(2)*sqrt(2) periodicity emerges. Remarkably,
the position of the coherence peaks exhibits evident particle-hole asymmetry
which also modulates with the same period. We propose that this is an extreme
quasiparticle interference phenomenon, caused by pairing-breaking scattering
between flat anti-nodal Bogoliubov bands, which is ultimately responsible for
the superconductor to metal transition.
