Influence of higher-order electron-phonon interaction on the electron-related lattice thermal properties of two-dimensional Dirac crystals
Bibliographic record
Abstract
Understanding the numerous crucial properties of Dirac crystals, such as their thermal conductivity, necessitates the use of models that consider the interaction between Dirac electrons and persistent acoustic phonons in which the oscillation frequency $\ensuremath{\omega}$ depends on the phonon wave vector $q$ and is therefore dispersive. It is commonly assumed that the exceptionally high thermal conductivity of two-dimensional (2D) Dirac crystals is due to the near ideality of their phonon quantum gasses with undesired limitations originating from phenomena such as electron-phonon ($e$-ph) interactions. Electrons transferred to Dirac crystals from metal nanoparticles through doping have been shown to affect and limit the thermal conductivity of Dirac crystals due to $e$-ph interactions at distances up to several microns from the nanoparticle. Notably, the $e$-ph thermal conductivity is directly linked to the phonon scattering rate, demonstrating a proportional relationship. Customarily, when calculating the phonon scattering rate, it is common to overlook phonons with short-dispersive wavelengths since in metals $q$ is significantly smaller than the Fermi surface dimensions. However, this approach proves insufficient for analyzing 2D Dirac crystals. Furthermore, the in-plane phonon scattering rate is calculated up to the first order of magnitude consisting of two electrons and one phonon, i.e., three-particle interaction. In these calculations, only processes involving the decay of an electron and phonon, leading to the creation of a new electron (EP-E*), are considered. However, processes that involve the decay of an electron and the creation of a new electron and phonon (E-E*P*) are not taken into consideration. In this paper, we present an accurate expression for the phonon scattering rate and the $e$-ph thermal conductivity in 2D Dirac crystals for in-plane phonons considering phonons with short-dispersive wavelengths. We further demonstrate that even at room temperature, when calculating the phonon scattering rate and $e$-ph thermal conductivity, in the case of first-order $e$-ph interactions, the E-E*P* process assumes significance. In the end, we show the importance of incorporating second-order $e$-ph interactions, particularly the (EP-E*P*) interaction involving the decay of an electron and phonon and the creation of a new pair for in-plane phonons, when determining the phonon scattering rate and $e$-ph thermal conductivity at high temperatures and low Fermi energies. This four-particle interaction process proves significant in accurately characterizing these properties.
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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 | 0.001 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.001 | 0.000 |
| Bibliometrics | 0.000 | 0.000 |
| Science and technology studies | 0.001 | 0.001 |
| Scholarly communication | 0.001 | 0.001 |
| Open science | 0.001 | 0.001 |
| Research integrity | 0.000 | 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".