  A novel superconducting state under the broken time-reversal symmetry is
studied in conventional phonon-mediated superconductors. By solving the
Eliashberg equation self-consistently with the mass renormalization effect, it
is found that the even- and odd-frequency components of the order parameter
coexist in the bulk system as a consequence of the broken time-reversal
symmetry. This finding would direct more attention to the odd-frequency pairing
that affects physical quantities, especially in strong coupling
superconductors.
