Investigating the <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mrow> <mml:mn>4</mml:mn> <mml:msub> <mml:mi>D</mml:mi> <mml:mrow> <mml:mn>3</mml:mn> <mml:mo>/</mml:mo> <mml:mn>2</mml:mn> </mml:mrow> </mml:msub> <mml:mrow> <mml:mo>|</mml:mo> <mml:mn>3</mml:mn> <mml:mo>,</mml:mo> <mml:mo>±</mml:mo> <mml:mn>2</mml:mn> <mml:mo>〉</mml:mo> </mml:mrow> </mml:mrow> </mml:math> – <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mrow> <mml:mn>4</mml:mn> <mml:msub> <mml:mi>D</mml:mi> <mml:mrow> <mml:mn>5</mml:mn> <mml:mo>/</mml:mo> <mml:mn>2</mml:mn> </mml:mrow> </mml:msub> <mml:mrow> <mml:mo>|</mml:mo> <mml:mn>3</mml:mn> <mml:mo>,</mml:mo> <mml:mo>±</mml:mo> <mml:mn>2</mml:mn> <mml:mo>〉</mml:mo> </mml:mrow> </mml:mrow> </mml:math> transition in <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:msup> <mml:mrow> <mml:mi>Nb</mml:mi> </mml:mrow> <mml:mrow> <mml:mn>4</mml:mn> <mml:mo>+</mml:mo> </mml:mrow> </mml:msup> </mml:math> for a THz atomic clock
Bibliographic record
Abstract
In this work, the $4{D}_{3/2}|3,\ifmmode\pm\else\textpm\fi{}2\ensuremath{\rangle}\ensuremath{\rightarrow}4{D}_{5/2}|3,\ifmmode\pm\else\textpm\fi{}2\ensuremath{\rangle}$ transition in the ${\mathrm{Nb}}^{4+}$ ion is identified as a promising candidate for a terahertz (THz) atomic clock, with the transition frequency occurring at 56.022 4 THz. This transition is primarily driven by the magnetic dipole decay channel, which can easily be accessed by a laser. We focus on the stable $^{93}\mathrm{Nb}$ isotope, which has 100% natural abundance and a nuclear spin of $I=9/2$ for experimental advantage. Our data analysis allows us to estimate potential systematic shifts in the proposed clock system, including those due to blackbody radiation, electric quadrupole, second-order Zeeman, and second-order Doppler shifts. The scheme presented in this study can help suppress the ac Stark and electric quadrupole shifts in the clock-frequency measurement. All these analyses suggest that the proposed THz atomic clock using ${\mathrm{Nb}}^{4+}$ could be valuable in both quantum thermometry and frequency metrology.
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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 | 0.008 | 0.025 |
| Meta-epidemiology (narrow) | 0.002 | 0.002 |
| Meta-epidemiology (broad) | 0.001 | 0.003 |
| Bibliometrics | 0.004 | 0.004 |
| Science and technology studies | 0.004 | 0.002 |
| Scholarly communication | 0.016 | 0.023 |
| Open science | 0.005 | 0.006 |
| Research integrity | 0.004 | 0.006 |
| Insufficient payload (model declined to judge) | 0.167 | 0.132 |
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".