Nonsequential Double Ionization by Circularly Polarized Laser Pulses: Recollisions Triggered by Nanotips

Strong field-induced nonsequential double ionization (NSDI) is a significant multi-electron phenomenon that provides crucial insights into understanding electron correlation and multiple ionization of atoms and molecules, but it is typically unattainable in a circularly polarized laser pulse, especially for the long wavelength laser. We present evidence that NSDI can occur in the presence of a near infrared or beyond laser pulse by introducing a bowtie-nanotip. The laser-induced local plasmon can alter the local ellipticity of the field, thereby enabling NSDI through elliptical trajectories that facilitate recollisions with parent atoms. An oval shaped momentum distribution of recoiled ions provides evidence for the modification of trajectories by the aligned nanotips. Our study introduces an innovative control knob to manipulate NSDI and electron dynamics through the utilization of nanostructures.