Tunneling Ionization Time Resolved by Backpropagation

Abstract

We determine the ionization time in tunneling ionization by an elliptically polarized light pulse relative to its maximum. This is achieved by a full quantum propagation of the electron wave function forward in time, followed by a classical backpropagation to identify tunneling parameters, in particular, the fraction of electrons that has tunneled out. We find that the ionization time is close to zero for single active electrons in helium and in hydrogen if the fraction of tunneled electrons is large. We expect our analysis to be essential to quantify ionization times for correlated electron motion.

Under-the-Tunneling-Barrier Recollisions in Strong-Field Ionization

“…Furthermore, the interference structures in the high-resolution photoelectron momentum distribution (PMD), created by the direct and recolliding trajectories, allow an interpretation as time-resolved holographic imaging of atoms and molecules, which admits attosecond time-and Ångström spatial-resolution [11][12][13][14]. For a correct interpretation of imaging results of the PMD based attoscience applications, one needs to understand theoretically all PMD features in details.There are many theoretical approaches for the treatment of the tunneling delay time [15][16][17], leading to different solutions and to a debate on how to explain the photoelectron momentum distribution in attoclock experiments [17][18][19]. Although all alternative definitions of the tunneling delay time are equally valid theoretical concepts, the Wigner concept [20] is physically relevant to the measurement of the photoelectron momentum distribution in the attoclock setup in the quasistatic regime, as proved in a recent experiment [10].…”

“…There are many theoretical approaches for the treatment of the tunneling delay time [15][16][17], leading to different solutions and to a debate on how to explain the photoelectron momentum distribution in attoclock experiments [17][18][19]. Although all alternative definitions of the tunneling delay time are equally valid theoretical concepts, the Wigner concept [20] is physically relevant to the measurement of the photoelectron momentum distribution in the attoclock setup in the quasistatic regime, as proved in a recent experiment [10].…”

Crossover from tunneling to multiphoton ionization of atoms

“…The IT also lends credence to the strategy of Ni et.al. [9] who use classical mechanics to propagate numerically-calculated probability densities backwards in time to the tunnelling region.…”

“…More recent developments e.g. [4], [5], [6] contain extensions of the SFA and in certain cases fully numerical calculations are now available [7], [8], [9].…”

Numerical Detector Theory for the Longitudinal Momentum Distribution of the Electron in Strong Field Ionization

“…In recent researches, the SENE method has been proved a useful model in studying non-adiabatic tunneling process with a non-zero tunneling time delay [28,29].…”