  The excited state dynamics of correlated electron and electron-phonon systems
triggered by an oscillating electric-field pulse of large amplitude are
theoretically investigated. A "negative-temperature" state and inversion of
electron-electron and electron-phonon interactions are induced even by a
symmetric monocycle pulse. This fact is numerically demonstrated, using the
exact diagonalization method, in a band-insulator phase of one-dimensional
three-quarter-filled strongly dimerized extended Peierls-Hubbard and Holstein
models. When the total-energy increment is maximized as a function of the
electric field amplitude, the occupancy of the bonding and antibonding orbitals
is inverted to produce a negative-temperature state. Around this state, the
dependences of time-averaged electron-electron and electron-phonon correlation
functions on interaction parameters are opposite to those in the ground state.
