Recollision scenario without tunneling : Role of the ionic core potential

The standard model of strong laser physics, the recollision scenario, omits the ionic core potential after tunneling. Strikingly, although the Coulomb interaction drives all stages of recollision, the maximum energy the electrons bring back to the core is found by ignoring it. We resolve this long-standing paradox by showing that this good agreement stems from a fortuitous cancellation at high intensities. Instead of the three step model, we find that the Coulomb interaction can be fully integrated into a purely classical scenario that explains recollisions without invoking tunneling.