Highly charged<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mmultiscripts><mml:mi mathvariant="normal">W</mml:mi><mml:none/><mml:mrow><mml:mn>13</mml:mn><mml:mo>+</mml:mo></mml:mrow></mml:mmultiscripts><mml:mo>,</mml:mo><mml:mo> </mml:mo><mml:mmultiscripts><mml:mi>Ir</mml:mi><mml:none/><mml:mrow><mml:mn>16</mml:mn><mml:mo>+</mml:mo></mml:mrow></mml:mmultiscripts></mml:math>, and<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mmultiscripts><mml:mi>Pt</mml:mi><mml:none/><mml:mrow><mml:mn>17</mml:mn><mml:mo>+</mml:mo></mml:mrow></mml:mmultiscripts></mml:math>ions as promising optical clock candidates for probing variations of the fine-structure constant
Bibliographic record
Abstract
Transitions among the first three low-lying states in the highly charged $\mathrm{W}^{13+}, \mathrm{Ir}^{16+}$, and $\mathrm{Pt}^{17+}$ ions are found to be strongly forbidden with wavelengths in the optical regime. By determining their energy levels, lifetimes, and other spectroscopic properties that are decisive quantities for estimating dominant systematics due to stray electromagnetic interactions in an experiment, we demonstrate that it can be possible to measure frequencies of the lowest forbidden transitions below a ${10}^{\ensuremath{-}19}$ precision level in the above ions, and hence, they seem to be suitable for frequency standards. We employ a sophisticated relativistic coupled cluster method to carry out calculations of these properties of the above states involving $4f$- and $5s$-core orbitals. We also found, by estimating their relativistic sensitivity coefficients, that these clock transitions can be highly sensitive to the tiny drift in the fine-structure constant ${\ensuremath{\alpha}}_{e}$. Consequently, a clock based on one of these ions, particularly $\mathrm{Pt}^{17+}$, could be used for corroborating the hypothesis of temporal and spatial variation in ${\ensuremath{\alpha}}_{e}$.
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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 | 0.002 | 0.007 |
| Meta-epidemiology (narrow) | 0.004 | 0.003 |
| Meta-epidemiology (broad) | 0.002 | 0.003 |
| Bibliometrics | 0.002 | 0.003 |
| Science and technology studies | 0.003 | 0.001 |
| Scholarly communication | 0.009 | 0.010 |
| Open science | 0.005 | 0.004 |
| Research integrity | 0.004 | 0.005 |
| Insufficient payload (model declined to judge) | 0.462 | 0.608 |
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".