Thermopower of a double quantum well based on GaAs
Bibliographic record
Abstract
The resistivity and thermopower of a double quantum well have been investigated in the temperature range $0.3\ensuremath{-}4.2\mathrm{K}$ as a function of voltage applied to a top gate. As in previous studies, the resistivity showed a strong resonance when the carrier densities in each well were approximately the same. In contrast, neither diffusion nor phonon-drag thermopower showed any sensitivity to the resonance. We have calculated the thermopower based on a model of two independent two-dimensional electron gases (2DEG's) connected in parallel. In the case of phonon-drag thermopower, ${S}^{g},$ it was necessary to take into account the mutual screening of the electron-phonon interaction by electrons in each layer and also the local-field correction to the static dielectric function. We find that ${S}^{g}$ exhibits a ${T}^{5}$ dependence at low temperatures instead of the standard ${T}^{4}$ expected for single GaAs quantum wells. We also find that, for the lowest densities examined, the local-field correction enhances the magnitude of the calculated ${S}^{g}$ by over a factor of 2, in good agreement with experiment. As a check on the model of two independent 2DEG's we have also calculated ${S}^{g}$ at resonance taking into account interwell coupling. The calculated values of ${S}^{g}$ so obtained are in good agreement with those obtained for uncoupled wells. This confirms the experimental result that ${S}^{g}$ is insensitive to the resonance condition.
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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 | 0.000 | 0.000 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 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) | 0.001 | 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".