Phase Competition in the Palmer-Chalker <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mi>X</mml:mi><mml:mi>Y</mml:mi></mml:math> Pyrochlore <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mrow><mml:msub><mml:mrow><mml:mi>Er</mml:mi></mml:mrow><mml:mrow><mml:mn>2</mml:mn></mml:mrow></mml:msub><mml:msub><mml:mrow><mml:mi>Pt</mml:mi></mml:mrow><mml:mrow><mml:mn>2</mml:mn></mml:mrow></mml:msub><mml:msub><mml:mrow><mml:mi mathvariant="normal">O</mml:mi></mml:mrow><mml:mrow><mml:mn>7</mml:mn></mml:mrow></mml:msub></mml:mrow></mml:math>
Bibliographic record
Abstract
We report neutron scattering measurements on ${\mathrm{Er}}_{2}{\mathrm{Pt}}_{2}{\mathrm{O}}_{7}$, a new addition to the $XY$ family of frustrated pyrochlore magnets. Symmetry analysis of our elastic scattering data shows that ${\mathrm{Er}}_{2}{\mathrm{Pt}}_{2}{\mathrm{O}}_{7}$ orders into the $k=0$, ${\mathrm{\ensuremath{\Gamma}}}_{7}$ magnetic structure (the Palmer-Chalker state), at ${T}_{N}=0.38\text{ }\text{ }\mathrm{K}$. This contrasts with its sister $XY$ pyrochlore antiferromagnets ${\mathrm{Er}}_{2}{\mathrm{Ti}}_{2}{\mathrm{O}}_{7}$ and ${\mathrm{Er}}_{2}{\mathrm{Ge}}_{2}{\mathrm{O}}_{7}$, both of which order into ${\mathrm{\ensuremath{\Gamma}}}_{5}$ magnetic structures at much higher temperatures, ${T}_{N}=1.2$ and 1.4 K, respectively. In this temperature range, the magnetic heat capacity of ${\mathrm{Er}}_{2}{\mathrm{Pt}}_{2}{\mathrm{O}}_{7}$ contains a broad anomaly centered at ${T}^{*}=1.5\text{ }\text{ }\mathrm{K}$. Our inelastic neutron scattering measurements reveal that this broad heat capacity anomaly sets the temperature scale for strong short-range spin fluctuations. Below ${T}_{N}=0.38\text{ }\text{ }\mathrm{K}$, ${\mathrm{Er}}_{2}{\mathrm{Pt}}_{2}{\mathrm{O}}_{7}$ displays a gapped spin-wave spectrum with an intense, flat band of excitations at lower energy and a weak, diffusive band of excitations at higher energy. The flat band is well described by classical spin-wave calculations, but these calculations also predict sharp dispersive branches at higher energy, a striking discrepancy with the experimental data. This, in concert with the strong suppression of ${T}_{N}$, is attributable to enhanced quantum fluctuations due to phase competition between the ${\mathrm{\ensuremath{\Gamma}}}_{7}$ and ${\mathrm{\ensuremath{\Gamma}}}_{5}$ states that border each other within a classically predicted phase diagram.
Fetched live from OpenAlex and de-inverted. Abstracts are not stored in this database: the inverted indexes are 8.6 GB of the frame’s 9.3 GB of text, and the host has 13 GB free.
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 | 0.007 | 0.005 |
| Meta-epidemiology (narrow) | 0.004 | 0.009 |
| Meta-epidemiology (broad) | 0.002 | 0.010 |
| Bibliometrics | 0.002 | 0.005 |
| Science and technology studies | 0.007 | 0.008 |
| Scholarly communication | 0.007 | 0.008 |
| Open science | 0.011 | 0.009 |
| Research integrity | 0.007 | 0.009 |
| Insufficient payload (model declined to judge) | 0.886 | 0.011 |
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".