  The $^{66}$Ge and $^{68}$Ge nuclei are studied by means of the shell model
with the extended $P+QQ$ Hamiltonian, which succeeds in reproducing
experimentally observed energy levels, moments of inertia and other properties.
The investigation using the reliable wave-functions predicts T=0, J=9
one-proton-one-neutron ($1p1n$) alignment in the $g_{9/2}$ orbit, at high spins
($14_1^+$, $16_1^+$ and $18_1^+$) in these $N \approx Z$ even-even nuclei. It
is shown that a series of the even-$J$ positive-parity yrast states (observed
up to $26_1^+$ for $^{68}$Ge) consists of the ground-state band and successive
three bands with different types of particle alignments (two-neutron, $1p1n$,
two-proton-two-neutron) in the $g_{9/2}$ orbit.
