Multiphoton Rabi Oscillations of Correlated Electrons in Strong Field Nonsequential Double Ionization

TL;DR

This paper reports the discovery of multiphoton Rabi oscillations in correlated electrons during double ionization of helium atoms under intense ultraviolet laser fields, revealing new insights into electronic correlations and multiphoton dynamics.

Contribution

It uncovers a previously unobserved double-circle structure in electron momentum spectra, demonstrating a two-electron multiphoton Rabi effect supported by quantum calculations.

Findings

Observation of double-circle structure in electron spectra

Identification of multiphoton Rabi oscillations of two electrons

Support from oscillating populations of doubly excited states

Abstract

With quantum calculations, we have investigated the multiphoton nonsequential double ionization of helium atoms in intense laser fields at ultraviolet wavelengths. Very surprisingly, we find a so-far unobserved double-circle structure in the correlated electron momentum spectra. The double-circle structure essentially reveals multiphoton Rabi oscillations of two electrons, which are strongly supported by the oscillating population of a certain doubly excited state and by the oscillating double ionization signals. This two-electron multiphoton Rabi effect provides profound understandings of electronic correlations and complicated multiphoton phenomena and is expected to be a new tool for broad applications, such as quantum coherent control.