  We carry out a systematic study of electric dipole mode (E1) for neutron-rich
isotopes from nickel (Z=28) to tin (Z=50) using a time-dependent mean-field
theory. Our time-dependent scheme is the canonical-basis time-dependent
Hartree-Fock-Bogoliubov theory which can self-consistently describe nuclear
dynamics with pairing correlation. We focus our discussion on the pygmy dipole
resonance (PDR) and E1 polarizability. The correlation between neutron-skin
thickness and PDR strongly depends on the neutron number, but the correlation
between the skin thickness and E1 polarizability is much more stable.
