Superposition of electron-hole density gratings in GaAs generated by quantum control of charge densities and charge currents
Bibliographic record
Abstract
Quantum interference of single-photon and two-photon absorption of 775 and $1550\phantom{\rule{0.3em}{0ex}}\mathrm{nm}$, $\ensuremath{\sim}150\phantom{\rule{0.3em}{0ex}}\mathrm{fs}$ optical pulses in GaAs at $300\phantom{\rule{0.3em}{0ex}}\mathrm{K}$ is known to lead to coherent control of electron-hole pair density and charge currents with the magnitude controlled by the pulses' relative phase and polarization. When the pulses are noncollinearly incident on a (001) GaAs crystal, the relative phase between the pulses varies in the plane of the surface, resulting in current and density gratings. The current grating also produces a charge-neutral electron-hole pair density grating following the completion of dielectric relaxation by the end of the pulses. The two types of density gratings, which are monitored using $830\phantom{\rule{0.3em}{0ex}}\mathrm{nm}$, $150\phantom{\rule{0.3em}{0ex}}\mathrm{fs}$ pulses and which decay by ambipolar diffusion and recombination on a $15\phantom{\rule{0.3em}{0ex}}\mathrm{ps}$ time scale, are studied as a function of sample azimuthal orientation and pulse polarization. For those polarizations where both density gratings are simultaneously generated, the amplitude of the current-induced density grating is comparable to that of the directly deposited grating and independent of grating period, although the former is related to a third-order optical process and the latter to a second-order process. Superposition and interference of the density gratings are therefore observed, as shown from the azimuthal dependence of the diffraction efficiency.
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How this classification was reachedexpand
Full frame distilled prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. Learned from the 10,348 direct Codex labels and 10,348 direct Gemma labels. Candidate is the union of thresholded teacher heads; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels or direct frontier model labels.
Codex and Gemma teacher scores by category
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.000 | 0.000 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.001 | 0.000 |
| Bibliometrics | 0.000 | 0.000 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.000 | 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 teacher head, 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".