REVIEW 4 major objections 5 minor 1 cited by
Absence of superconductivity and density-wave transition in ambient-pressure tetragonal La$_4$Ni$_3$O$_{10}$
T0 review · 4 major / 5 minor · reviewed 2026-08-10 · deepseek-v4-flash
Pith's one-line read Ambient-pressure tetragonal La4Ni3O10 never superconducts up to 160 GPa.
desk verdict A clean negative result with a genuinely new material; the high-pressure structural gap above 27.7 GPa keeps the central interpretation from being fully sealed. read the letter →
The pith
A machine-rendered reading of the paper's core claim, the machinery that carries it, and where it could break.
The reading
What carries the argument
The central object is the ambient-pressure tetragonal phase of La4Ni3O10 (I4/mmm, no octahedral tilting), synthesized under flowing oxygen. The argument proceeds by comparing transport, magnetic torque, and DFT band structures across three phases: monoclinic P21/a at ambient pressure, tetragonal I4/mmm at high pressure (from prior work), and the new tetragonal I4/mmm at ambient pressure. The key comparison is that the monoclinic phase hosts a density-wave transition and becomes superconducting when pressurized into the tetragonal structure, whereas the ambient-pressure tetragonal phase, which never enters a density-wave state, also never superconducts. This decouples the tetragonal lattice symmetry from superconductivity and identifies the density-wave order as the variable that tracks the appearance of superconductivity.
What would settle it
High-pressure X-ray diffraction of the ambient-pressure tetragonal La4Ni3O10 above 27.7 GPa that reveals a structural phase transition would invalidate the conclusion, because the absence of superconductivity could then be attributed to a different crystal structure rather than to the intrinsic electronic state of the tetragonal phase.
Extended reading notes
Core claim
By growing La4Ni3O10 in a high-oxidative environment, the authors stabilize the I4/mmm tetragonal structure without octahedral tilting at ambient pressure, confirmed by single-crystal X-ray diffraction, electron diffraction, and powder X-ray diffraction up to 27.7 GPa. Transport and magnetic torque measurements show no density-wave transition in this tetragonal phase, and high-pressure resistance measurements up to 160 GPa find no superconductivity. In contrast, monoclinic La4Ni3O10 shows a density-wave transition near 135 K and superconductivity above about 20 GPa, with a structural transition to the tetragonal phase accompanying the onset of superconductivity. The simultaneous absence of both density-wave order and superconductivity in the ambient-pressure tetragonal phase leads the authors to conclude that the tetragonal structure is not sufficient for superconductivity and that the density-wave state is crucial. DFT calculations show that the ambient-pressure tetragonal phase has extra $d_{z^2}$-derived Fermi pockets that disappear under pressure, yet superconductivity is absent both with and without these pockets, arguing against a critical role for the $d_{z^2}$ orbital contribution.
Load-bearing premise
The conclusion that the tetragonal phase itself lacks superconductivity depends on the premise that the ambient-pressure tetragonal structure remains the same I4/mmm phase up to 160 GPa, but powder X-ray diffraction was only measured up to 27.7 GPa.
Editorial extensions
If this is right
- Tetragonal symmetry of the NiO6 octahedra is not sufficient for superconductivity in trilayer nickelates.
- The density-wave state, or an electronic order tightly coupled to it, may be a necessary precursor for pressure-induced superconductivity in these materials.
- The absence of superconductivity up to 160 GPa rules out simple structural arguments based solely on lattice symmetry and tilting angles.
- The near-stoichiometric oxygen content, verified by diffraction refinement and electron microscopy, indicates that oxygen deficiency does not explain the absence of superconductivity.
Reading between the lines
- If the density-wave order is the load-bearing ingredient, then a more direct route to ambient-pressure superconductivity in nickelates might be to stabilize a density-wave state at ambient pressure rather than merely achieving a tetragonal lattice.
- The Lifshitz transition near 20 GPa in the tetragonal phase removes the extra $d_{z^2}$ pockets but does not restore superconductivity, suggesting the missing ingredient is the electronic correlations associated with the density wave, not the $d_{z^2}$ orbital character itself.
- One testable extension is to synthesize an ambient-pressure tetragonal La3Ni2O7 and check whether it also lacks superconductivity under pressure; the paper's logic predicts it would, because no density-wave order would be present initially.
Signed reviews
Editorial analysis
A structured set of objections, weighed in public.
Referee Report
Summary. The paper reports the synthesis of ambient-pressure tetragonal (I4/mmm) La4Ni3O10 microcrystals using a high-oxidative-environment growth method and presents transport, magnetic torque, powder XRD, and DFT results. The key claims are that this tetragonal phase shows no density-wave transition at ambient pressure and no superconductivity up to 158.9 GPa, in contrast to the monoclinic phase which becomes superconducting after a pressure-induced structural transition to tetragonal. The authors interpret this as evidence that the tetragonal structure alone is not sufficient for superconductivity and that the density-wave order, or an associated electronic state, is crucial.
Significance. If correct, the paper provides a strong experimental constraint on theories of pressure-induced superconductivity in Ruddlesden-Popper nickelates: it suggests that the density-wave state is a necessary ingredient for superconductivity, rather than merely the tetragonal symmetry. The synthesis of an ambient-pressure tetragonal phase without octahedral tilting is an important materials achievement. The paper includes machine-accessible structural refinements, transport data to 158.9 GPa on two tetragonal samples, ambient-pressure magnetic torque, XRD to 27.7 GPa, and auxiliary DFT calculations; the central negative transport result is not dependent on fitted parameters. However, the structural persistence to the highest pressures, which underpins the interpretation of the negative result, is experimentally verified only to 27.7 GPa, leaving a significant gap.
major comments (4)
- [§2, Fig. 2f, Extended Data Fig. 4] The conclusion that the tetragonal I4/mmm structure persists up to 160 GPa is not supported by the data: powder XRD is reported only to 27.7 GPa, while the high-pressure transport on samples S3 and S4 extends to ~60 GPa and 158.9 GPa, respectively, with no in-situ structural confirmation. If a structural phase transition, amorphization, or chemical reaction occurs above 27.7 GPa, the absence of superconductivity could be due to a different crystal structure rather than the intrinsic electronic state of the ambient-pressure tetragonal phase. Since the paper's central interpretive claim (that the tetragonal structure is not necessary) rests on this structural equivalence, the authors should either provide structural data at higher pressures or explicitly qualify the conclusions as applying to the measured structural range.
- [§4, Fig. 4, §5 Discussion] The DFT results reveal substantial differences between the ambient-pressure tetragonal (I4/mmm-AP) and high-pressure tetragonal (I4/mmm-HP) phases: the AP phase has additional dz2-derived Fermi pockets that disappear with pressure, indicating a Lifshitz transition. Yet the text in §2 describes the two tetragonal phases as 'almost identical.' This inconsistency matters because the argument that the tetragonal structure is not sufficient for superconductivity assumes that the AP tetragonal phase becomes electronically equivalent to the HP superconducting phase under pressure. The authors should reconcile these statements and discuss whether the differences in electronic structure might themselves explain the absence of superconductivity.
- [§5 Discussion and Methods] The manuscript acknowledges that precise oxygen content is difficult to determine and states that the oxygen content of the I4/mmm-AP phase is slightly larger than that of the P21/a-AP phase by ~0.04. While XRD refinement and iDPC imaging suggest near-stoichiometry, a small oxygen off-stoichiometry could in principle suppress superconductivity or alter the density-wave order. The negative result would be more convincing if the authors provided a more quantitative comparison of oxygen content between the tetragonal and monoclinic samples (e.g., via a direct measurement method) or a discussion of the known sensitivity of superconductivity to small oxygen vacancies in these nickelates.
- [Methods: High pressure transport] The methods state that either NaCl or Daphne oil 7373 was used as the pressure-transmitting medium, but it is not specified which sample (S1–S4) used which medium. Non-hydrostatic or quasi-hydrostatic conditions can suppress superconductivity and may also influence structural transitions, so this information is essential for evaluating the negative results. Please specify the medium, pressure range, and any evidence for hydrostaticity for each sample.
minor comments (5)
- [Introduction] The text reads 'the titled NiO6 octahedron' and 'a titled Ni-O-Ni bond'; this should be 'tilted' throughout.
- [Methods: Structural characterization] The phrase 'results with a moderalate R1 and wR2' contains a typo; it should say 'moderate R1 and wR2.'
- [Fig. 2g] The figure caption states 'the two diffraction peaks can be well indexed by (107) and (110) for a tetragonal structural phase'; this is redundant, as 'tetragonal' already implies the structural phase, and the sentence could be shortened.
- [Abstract] The abstract says 'orthogonal/monoclinic structure' for the parent nickelates; 'orthogonal' is an unconventional term for crystalline lattices, and 'orthorhombic' would be the standard descriptor for La3Ni2O7.
- [§1, Fig. 1e] The phase diagram is described as determined by data in Fig. 3a and 3b and Extended Data Fig. 7, but the structural boundary is taken from references [15,16]; this should be clearly indicated in the figure caption to avoid overstating the provenance of the structural transition line.
Circularity Check
No significant circularity: the central claim is an experimentally measured negative result with independent structural and transport controls.
full rationale
The paper's central claim—that ambient-pressure tetragonal La4Ni3O10 shows neither a density-wave transition nor superconductivity up to 160 GPa—rests on direct transport and magnetic torque measurements on multiple tetragonal samples, not on a derived quantity. Structural identification is performed independently by single-crystal X-ray diffraction, selected-area electron diffraction, and powder XRD up to 27.7 GPa, with high-pressure transport extending to 158.9 GPa on sample S4. No fitted parameter is fed into the main experimental conclusion, and the DFT calculations are auxiliary: they compare Fermi surfaces among three known crystal structures and do not generate the transport result. The comparison with monoclinic La4Ni3O10 uses published high-pressure structural and superconducting data as external benchmarks, not as a self-citation chain that defines the conclusion. The known evidence gap—that powder XRD is not reported above 27.7 GPa, so persistence of the I4/mmm structure to 160 GPa is an assumption—is a correctness/verification concern, not circularity. No equation, definition, or fitted quantity reduces the claimed result to its own input, so the appropriate circularity score is 0.
Assumptions & free parameters
free parameters (1)
- Hubbard U in DFT+U =
not reported in main text; scanned over values
assumptions (4)
- domain assumption DFT with meta-GGA+U captures the relevant electronic structure of La4Ni3O10.
- domain assumption Resistance measurements can rule out superconductivity and density-wave order.
- domain assumption The tetragonal I4/mmm structure persists from ambient pressure to 160 GPa.
- domain assumption The as-grown crystals are near-stoichiometric.
Cite this review
Pith. "Pith review of Absence of superconductivity and density-wave transition in ambient-pressure tetragonal La$_4$Ni$_3$O$_{10}$." pith.science (2026). https://pith.science/paper/6IQW7FRU
@misc{pith2026250112647,
author = {Pith},
title = {Pith review of: Absence of superconductivity and density-wave transition in ambient-pressure tetragonal La$_4$Ni$_3$O$_10$},
year = {2026},
howpublished = {\url{https://pith.science/paper/6IQW7FRU}},
note = {Machine review of arXiv:2501.12647}
}
abstract
The recent discovery of superconductivity in La$_3$Ni$_2$O$_7$ and La$_4$Ni$_3$O$_{10}$ under high pressure stimulates intensive research interests. These nickelates crystallize in an orthogonal/monoclinic structure with tilted NiO$_6$ octahedra at ambient pressure and enter a density-wave-like phase at low temperatures. The application of pressure suppresses the octahedral tilting and triggers a transition to tetragonal structure (I4/mmm), which is believed to be a key prerequisite for the emergence of superconducting state. Here, by developing a high oxidative environment growth technology, we report the first tetragonal nickelates La$_4$Ni$_3$O$_{10}$ microcrystals without octahedral tilting at ambient pressure. In tetragonal La$_4$Ni$_3$O$_{10}$, transport measurements find that both density-wave and superconducting transitions are absent up to 160 GPa, indicating a robust tetragonal metallic ground state. Density functional theory calculations reveal that the band structure of ambient-pressure tetragonal La$_4$Ni$_3$O$_{10}$ involves more $d_{z2}$ orbital contribution to the Fermi surface, compared to the monoclinic phase or the high-pressure superconducting tetragonal phase. The concurrent absence of density-wave state and high-pressure superconductivity in our ambient-pressure tetragonal crystals of La$_4$Ni$_3$O$_{10}$ suggests an underlying correlation between these two orders. It suggests that the tetragonal structure is not necessary, while the density-wave state is crucial for the superconductivity in nickelates. Our findings impose important constraints on the mechanism of pressure-induced superconductivity in nickelates and sheds new light on exploring ambient pressure high-temperature Ni-based superconductors.
Forward citations
Cited by 1 Pith paper
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Signature of superconductivity in pressurized La4Ni3O10-x single crystals grown at ambient pressure
Ambient-pressure flux-grown La4Ni3O10-x single crystals show a pressure-induced resistance drop and magnetic-field-suppressed Tc near 30 K at 77.9 GPa, a superconductivity signature matching floating-zone crystals.
Reviewed August 10, 2026 · model on record in the stance chip above.
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