Ionization with low-frequency fields in the tunneling regime

@article{Dur2013IonizationWL,
  title={Ionization with low-frequency fields in the tunneling regime},
  author={Judith Dur{\'a} and Nicolas Camus and Alexandre Thai and Alexander Britz and Michael Hemmer and Matthias Baudisch and Arne Senftleben and Claus Dieter Schr{\"o}ter and Joachim Ullrich and Robert Moshammer and Jens Biegert},
  journal={Scientific Reports},
  year={2013},
  volume={3}
}
Strong-field ionisation surprises with richness beyond current understanding despite decade long investigations. Ionisation with mid-IR light has promptly revealed unexpected kinetic energy structures that seem related to unanticipated quantum trajectories of the electrons. We measure first 3D momentum distributions in the deep tunneling regime (γ = 0.3) and observe surprising new electron dynamics of near-zero momentum electrons and extremely low momentum structures, below the eV, despite very… 

Origins of Very-Low and Zero-Energy Electron Structures in Strong-Field Ionization with Intense Mid-IR Pulses

Intense long wavelength (λ ≥ 2 μm) laser pulses enable experiments in the tunneling ionization regime (γ ≪ 1) and reveal surprising low electron energy features, which can not be described with the

Momentum Distribution of Near-Zero-Energy Photoelectrons in the Strong-Field Tunneling Ionization in the Long Wavelength Limit

TLDR
A surprising accumulation in the momentum distribution corresponding to meV energy and a “V”-like structure at the slightly larger transverse momenta is found in the ionization dynamics of Argon atoms irradiated by an ultrashort intense laser.

Kinematically complete measurements of strong field ionization with mid-IR pulses

Recent observations of three unique peaks near 1 eV, 100 meV and 1 meV in the electron spectra generated by ionization using intense mid-IR pulses have challenged the current understanding of

Above-threshold ionization for very low electron energy

The rescattering term of the ionization amplitude in the strong-field approximation is analyzed for very low electron energy and emission in arbitrary direction, first in terms of the classical

Strong-field physics with mid-IR fields

Strong-field physics is currently experiencing a shift towards the use of mid-IR driving wavelengths. This is because they permit conducting experiments unambiguously in the quasi-static regime and

High-energy direct photoelectron spectroscopy in strong-field ionization

Recently, in a strong Coulomb field regime of tunneling ionization an unexpected large enhancement of photoelectron spectra due to the Coulomb field of the atomic core has been identified by

Low-energy electron rescattering in laser-induced ionization

The low-energy structure (LES) in the energy spectrum of above-threshold ionization of rare-gas atoms is reinvestigated from three different points of view. First, the role of forward rescattering in

Kinematic origin for near-zero energy structures in mid-IR strong field ionization

We propose and discuss a kinematic mechanism underlying the recently discovered ‘near-zero energy structure’ in the photoionization of atoms in strong mid-infrared laser fields, based on trajectories

Strong-field ionization of argon: Electron momentum spectra and nondipole effects

We investigate the influence of relativistic nondipole effects on the photoelectron spectra of argon, particularly in the low kinetic energy region (0 eV 5 eV). In our experiment, we use intense

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

TLDR
The interference of the direct and the under-the-barrier recolliding quantum orbits are shown to induce a measurable shift of the peak of the photoelectron momentum distribution, which allows the Wigner concept for the quasistatic tunneling time delay into the nonadiabatic domain.

References

SHOWING 1-10 OF 37 REFERENCES

Strong-field tunneling without ionization.

TLDR
In the tunneling regime of strong laser field ionization, a substantial fraction of neutral atoms surviving the laser pulse in excited states is measured, confirming the existence of a widely unexplored neutral exit channel (frustrated tunneling ionization).

Resonant structures in the low-energy electron continuum for single ionization of atoms in the tunnelling regime

We present high-resolution fully differential experimental data on single ionization of He, Ne and Ar by ultra-short (25 fs, 6 fs) 795 nm laser pulses at intensities 0.15–2.0 × 1015 W cm−2. We show

Coulomb singularity in the transverse momentum distribution for strong-field single ionization

We present high-resolution momentum distributions of ions and electrons created in single ionization of He, Ne and Ar targets by intense (0.15–2 PW cm−2) short-pulsed (25 fs) linearly polarized laser

Characteristic spectrum of very low-energy photoelectron from above-threshold ionization in the tunneling regime.

TLDR
The quantum and semiclassical analysis reveal the role of long-range Coulomb potential in the production of this very low-energy peak structure in tunneling ionization process from noble gas atoms interacting with ultrashort intense infrared laser pulses.

Low-energy peak structure in strong-field ionization by midinfrared laser pulses: Two-dimensional focusing by the atomic potential

We analyze the formation of the low-energy structure (LES) in above-threshold ionization spectra first observed by Quan et al. [1] and Blaga et al. [2] using both quasi-classical and quantum

Origin of unexpected low energy structure in photoelectron spectra induced by midinfrared strong laser fields.

TLDR
It is shown that the LES arises due to an interplay between multiple forward scattering of an ionized electron and the electron momentum disturbance by the Coulomb field immediately after the ionization.

Low-energy structures in strong field ionization revealed by quantum orbits.

TLDR
It is shown that a conceptually simple extension towards the inclusion of Coulomb effects yields very good agreement with exact TDSE results and the Coulomb quantum orbits allow for a physically intuitive interpretation and detailed analysis of all low-energy features in the semiclassical regime.

Low-energy structure of above-threshold-ionization electron spectra: Role of the Coulomb threshold effect

Recent experimental observations of above-threshold ionization of rare gas atoms and diatomic molecules by midinfrared laser fields [C. I. Blaga et al., Nat. Phys. 5, 335 (2009); W. Quan et al.,

Low yield of near-zero-momentum electrons and partial atomic stabilization in strong-field tunneling ionization.

TLDR
The refined transition between the Rydberg states of the stabilized atoms has implication on the THz radiation from gas targets in strong laser fields.

Capture into rydberg states and momentum distributions of ionized electrons

The yield of neutral excited atoms and low-energy photoelectrons generated by the electron dynamics in the combined Coulomb and laser field after tunneling is investigated. We present results of