  Excitonic density-wave states realized by the quantum condensation of
electron-hole pairs (or excitons) are studied in the two-band Hubbard model
with Hund's rule coupling and the pair hopping term. Using the variational
cluster approximation, we calculate the grand potential of the system and
demonstrate that Hund's rule coupling always stabilizes the excitonic
spin-density-wave state and destabilizes the excitonic charge-density-wave
state and that the pair hopping term enhances these effects. The
characteristics of these excitonic density-wave states are discussed using the
calculated single-particle spectral function, density of states, condensation
amplitude, and pair coherence length. Implications of our results in the
materials' aspects are also discussed.

Strongly Correlated Electrons