Frequency-domain theory of nonsequential double ionization in intense laser fields based on nonperturbative QED
Bibliographic record
Abstract
We study nonsequential double ionization (NSDI) processes of an atom by applying the frequency-domain theory based on the nonperturbative quantum electrodynamics. We obtain the transition formulas that describe the NSDI processes caused by the collision ionization (CI) and the collision-excitation ionization (CEI) mechanisms. By analyzing the NSDI results of each above-threshold ionization (ATI) channel, we investigate the contributions to the NSDI from the backward and forward collisions. In particular, for the CI process, the backward collision makes a major contribution to the NSDI probability, whereas for the CEI process, it depends on the characteristics of the laser-atom system: if the energy that the recolliding electron needs to excite a bound electron is much larger than the laser photon energy, such as for the case of helium in this work, the backward collision dominates the contribution; otherwise, the forward collision dominates the contribution. We also discuss the source of interference fringes in the NSDI momentum spectra due to the CI mechanism and find that the fringes can be predicted by using a simple cosine function. This work can be regarded as a development of the frequency-domain theory, which may shed light on the study of multiparticle dynamics in intense laser fields.
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How this classification was reachedexpand
Full frame machine prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. The Gemma side is a direct model label for every work in the frame, read from the title-only record. The Codex side is a classifier learned from the 10,348 direct Codex labels and calibrated to design-weighted sample rates; fields without enough sample support carry no Codex call. Candidate is the union of the two sides; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels.
Distilled classifier scores by category (both heads)
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.001 | 0.001 |
| Meta-epidemiology (narrow) | 0.001 | 0.000 |
| Meta-epidemiology (broad) | 0.001 | 0.001 |
| Bibliometrics | 0.001 | 0.001 |
| Science and technology studies | 0.001 | 0.002 |
| Scholarly communication | 0.001 | 0.002 |
| Open science | 0.001 | 0.001 |
| Research integrity | 0.001 | 0.001 |
| Insufficient payload (model declined to judge) | 0.002 | 0.000 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one source (direct Gemma or distilled Codex), not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".