Optical determination of the superconducting energy gap in electron-doped<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mrow><mml:msub><mml:mi mathvariant="normal">Pr</mml:mi><mml:mn>1.85</mml:mn></mml:msub><mml:msub><mml:mi mathvariant="normal">Ce</mml:mi><mml:mn>0.15</mml:mn></mml:msub><mml:mi mathvariant="normal">Cu</mml:mi><mml:msub><mml:mi mathvariant="normal">O</mml:mi><mml:mn>4</mml:mn></mml:msub></mml:mrow></mml:math>
Bibliographic record
Abstract
The optical properties of single crystal ${\mathrm{Pr}}_{1.85}{\mathrm{Ce}}_{0.15}\mathrm{Cu}{\mathrm{O}}_{4}$ have been measured over a wide frequency range above and below the critical temperature $({T}_{c}\ensuremath{\simeq}20\phantom{\rule{0.3em}{0ex}}\mathrm{K})$. In the normal state the coherent part of the conductivity is described by the Drude model, from which the scattering rate just above ${T}_{c}$ is determined to be $1∕\ensuremath{\tau}\ensuremath{\simeq}80\phantom{\rule{0.3em}{0ex}}{\mathrm{cm}}^{\ensuremath{-}1}$. The condition that $\ensuremath{\hbar}∕\ensuremath{\tau}\ensuremath{\approx}2{k}_{B}T$ near ${T}_{c}$ appears to be a general result in many of the cuprate superconductors. Below ${T}_{c}$ the formation of a superconducting energy gap is clearly visible in the reflectance, from which the gap maximum is estimated to be ${\ensuremath{\Delta}}_{0}\ensuremath{\simeq}35\phantom{\rule{0.3em}{0ex}}{\mathrm{cm}}^{\ensuremath{-}1}$ $(4.3\phantom{\rule{0.3em}{0ex}}\mathrm{meV})$. The ability to observe the superconducting energy gap in the optical properties favors the nonmonotonic over the monotonic description of the $d$-wave gap. The penetration depth for $T⪡{T}_{c}$ is $\ensuremath{\lambda}\ensuremath{\simeq}2000\phantom{\rule{0.3em}{0ex}}\mathrm{\AA{}}$, which when taken with the estimated value for the dc conductivity just above ${T}_{c}$ of ${\ensuremath{\sigma}}_{dc}\ensuremath{\simeq}35\ifmmode\times\else\texttimes\fi{}{10}^{3}\phantom{\rule{0.3em}{0ex}}{\ensuremath{\Omega}}^{\ensuremath{-}1}\phantom{\rule{0.2em}{0ex}}{\mathrm{cm}}^{\ensuremath{-}1}$ places this material on the general scaling line for the cuprates defined by $1∕{\ensuremath{\lambda}}^{2}\ensuremath{\propto}{\ensuremath{\sigma}}_{dc}(T\ensuremath{\simeq}{T}_{c})∙{T}_{c}$. These results are consistent with the observation that $1∕\ensuremath{\tau}\ensuremath{\approx}2{\ensuremath{\Delta}}_{0}$, which implies that the material is not in the clean limit.
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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 | 0.005 | 0.002 |
| Meta-epidemiology (narrow) | 0.003 | 0.005 |
| Meta-epidemiology (broad) | 0.001 | 0.005 |
| Bibliometrics | 0.001 | 0.004 |
| Science and technology studies | 0.004 | 0.004 |
| Scholarly communication | 0.003 | 0.007 |
| Open science | 0.006 | 0.005 |
| Research integrity | 0.004 | 0.005 |
| Insufficient payload (model declined to judge) | 0.506 | 0.004 |
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; both teacher heads agree on what is shown here.
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".