  $\Lambda N$ spin-spin and spin-orbit splittings in low-lying excitation
spectra are investigated for $p$-shell $\Lambda$ hypernuclei on the basis of
the microscopic structure calculation within the antisymmetrized molecular
dynamics, where the $\Lambda N$ $G$-matrix interaction derived from the
baryon-baryon interaction model ESC (extended soft core) is used. It is found
that the ground-state spin-parity is systematically reproduced in the $p$-shell
$\Lambda$ hypernuclei by tuning the $\Lambda N$ spin-spin and spin-orbit
interactions so as to reproduce the experimental data of $^{4}_\Lambda$H,
$^{7}_\Lambda$Li and $^9_\Lambda$Be. Furthermore, we also focus on the
excitation energies of the excited doublets as well as the energy shifts of
them by the addition of a $\Lambda$ particle.
