LAUSR

The one-photon ionization and tunneling ionization of H2 exposed to strong XUV and infrared laser pulses are studied by numerically simulating the four-dimensional time-dependent Schrödinger equation, which includes two-electron dynamics for arbitrary angle between the molecular axis and the laser polarization direction. In the one-photon single ionization of H2, one electron escapes fast and the other bound electron is not disturbed but remains in coherent superposition of two electronic states of $${{\bf{H}}}_{{\bf{2}}}^{{\boldsymbol{+}}}$$H2+. In another case, under the irradiation of strong infrared laser pulses, one electron tunnels through the laser-dressed Coulomb barrier, and the other bound electron has enough time to adapt to the potential of $${{\bf{H}}}_{{\bf{2}}}^{{\boldsymbol{+}}}$$H2+ and thus is prone to transfer to the ground electronic state of $${{\bf{H}}}_{{\bf{2}}}^{{\boldsymbol{+}}}$$H2+. In the intermediate regime, between the one photon and tunneling regimes, this electron-electron correlation depends strongly on the laser frequency, laser intensity and on the angle between laser polarization and the molecular axis.