Rescattering of Ultra Low-Energy Electrons for Single Ionization of Ne in the Tunneling Regime

Electron emission for single ionization of Ne by 25 fs, 1.0 PW/cm2 laser pulses at 800 nm has been investigated in a kinematically complete experiment using a "reaction microscope." Mapping the complete final state momentum space with high resolution, a distinct local minimum is observed at Pe = 0, where Pe is the electron momentum parallel to the laser polarization. Whereas tunneling theory predicts a maximum at zero momentum, our findings are in good agreement with recent semiclassical predictions which were interpreted to be due to "recollision.