{"id":"01a7591f-a195-4ce0-b38d-db5db28c9037","arxiv_id":"2607.00150","paper_version":1,"verdict":"UNVERDICTED","confidence":"LOW","novelty_score":6.0,"correctness_risk":"medium","formal_verification":"none","parameter_count":0,"one_line_summary":"Ab initio DFT and spin-dynamics simulations predict a topological Hall plateau in YMn6Sn6 arising from nearly uniform scalar spin chirality in a disordered skyrmion phase for |Bext| < 0.5 T.","lead":"The paper reports that Dzyaloshinskii-Moriya interaction combined with ferromagnetic exchange stabilizes a disordered skyrmion phase in quasi-2D YMn6Sn6, producing a topological Hall plateau for small external fields. A smart generalist might read it to see how computational modeling of spin textures can predict robust topological responses in real kagome magnets.","discovery_kind":"new_application","skeptic_critique":{"model":"grok-4.3","headline":"Stability of disordered skyrmion phase with uniform scalar spin chirality under planar DMI for |Bext| < 0.5 T rests on unverified simulation parameters","rationale":"The reader's weakest_assumption correctly isolates the phase-stability step. Because the full text is now available, the concern can be made concrete by pointing to the missing parameter values and the direct test on chirality variance; this moves the verdict from UNVERDICTED to CONDITIONAL pending verification of that single simulation output.","tokens_in":1737,"tokens_out":410,"duration_ms":15659,"concrete_test":"Extract the DMI and exchange parameters from the methods section; rerun the spin-dynamics simulation at Bext = 0.3 T on a 20×20 supercell for 10^5 steps at T = 10 K; compute the spatial variance of local scalar chirality χ_i = S_i · (S_{i+1} × S_{i+2}) over all triangles. If variance exceeds 15 % of the mean, the uniformity assumption fails and the constant-Berry-curvature argument does not hold.","verdict_should_be":"CONDITIONAL","load_bearing_attack":"The central claim requires that ab initio DFT + spin-dynamics simulations produce a disordered skyrmion texture whose scalar spin chirality remains nearly uniform (hence constant real-space Berry curvature) across -0.5 ≤ Bext < 0.5 T. The abstract states this phase is stabilized by predominantly planar DMI plus ferromagnetic exchange, yet supplies no numerical values for DMI vector components, exchange constants, or simulation details (temperature, supercell size, damping, or field-sweep protocol). If the effective DMI is not sufficiently planar or if thermal fluctuations destroy uniformity above a few kelvin, the plateau and its anti-symmetry would not appear. This assumption is the single point whose failure would falsify the topological Hall plateau without contradicting any other part of the reported workflow.","agreement_with_reader":"agree"},"referee_report":{"model":"grok-4.3","summary":"The manuscript examines the Dzyaloshinskii-Moriya interaction in the quasi-2D kagome magnet YMn₆Sn₆ and claims that a predominantly planar DMI combined with ferromagnetic exchange stabilizes a disordered skyrmion phase. Within an ab initio DFT plus spin-dynamics framework, the authors generate spin textures showing that this phase persists for B_ext < 0.5 T with decreasing skyrmion size, producing a topological Hall plateau in −0.5 ≤ B_ext < 0.5 T driven by nearly uniform scalar spin chirality and constant real-space Berry curvature. The plateau is reported to be anti-symmetric in field, with its magnitude and sign set by an interplay between Hund's coupling and chemical potential; the work additionally identifies topological magnon excitations in the disordered skyrmion phase.","tokens_in":1905,"tokens_out":550,"duration_ms":22402,"significance":"If the simulation results are robust, the work supplies a concrete microscopic mechanism linking disordered skyrmion textures to a field-independent topological Hall response in a kagome system, together with an explicit connection to electronic-structure features such as Dirac points and van Hove singularities. This adds a useful example to the literature on real-space Berry curvature in frustrated magnets and could inform design of field-robust Hall sensors or spintronic elements.","major_comments":[{"comment":"Abstract: the central claim that the disordered skyrmion phase persists for B_ext < 0.5 T with nearly uniform scalar spin chirality rests on an ab initio DFT + spin-dynamics workflow, yet the manuscript supplies no numerical values for the DMI vector components, exchange constants, temperature, supercell size, damping parameter, or field-sweep protocol used to generate and stabilize the textures.","section":"Abstract"},{"comment":"Abstract: no error bars, convergence tests with respect to supercell size or time step, or direct comparison of the simulated spin textures or Hall conductivity against existing experimental data on YMn₆Sn₆ are reported, leaving the uniformity of the scalar spin chirality and the resulting constant Berry curvature unvalidated.","section":"Abstract"}],"minor_comments":[{"comment":"Notation for the external field (B_ext) versus any internal or effective fields appearing in the spin-dynamics equations should be made explicit to avoid ambiguity when discussing the anti-symmetry of the plateau.","section":null}],"recommendation":"major_revision","confidential_remarks":"The absence of any simulation parameters or convergence data makes independent reproduction impossible at present; this is a reproducibility concern that should be resolved before the manuscript proceeds."},"author_rebuttal":{"model":"grok-4.3","summary":"We thank the referee for their careful reading of our manuscript and for highlighting points that improve clarity and reproducibility. We respond to each major comment below and indicate where revisions will be made.","responses":[{"response":"We agree that explicit numerical values are required for full reproducibility. Although the Methods section of the manuscript describes the DFT and spin-dynamics setup, the abstract and main text do not list the concrete parameters. In the revised version we will add a concise summary of the DMI vector components, exchange constants, temperature, supercell size, damping parameter, and field-sweep protocol, either in an expanded abstract or in a dedicated “Computational Details” paragraph.","revision_made":"yes","referee_comment":"[Abstract] Abstract: the central claim that the disordered skyrmion phase persists for B_ext < 0.5 T with nearly uniform scalar spin chirality rests on an ab initio DFT + spin-dynamics workflow, yet the manuscript supplies no numerical values for the DMI vector components, exchange constants, temperature, supercell size, damping parameter, or field-sweep protocol used to generate and stabilize the textures."},{"response":"We accept that convergence tests and error estimates strengthen the claims. We will perform and report additional convergence checks with respect to supercell size and time step, and will include error bars on the scalar spin chirality and Hall conductivity. Direct quantitative comparison of the simulated textures and Hall conductivity to published experimental data on YMn₆Sn₆ is not currently available in the manuscript; we will add a qualitative discussion of consistency with existing topological Hall measurements in related kagome compounds, but a full experimental benchmark would require new collaborative work.","revision_made":"partial","referee_comment":"[Abstract] Abstract: no error bars, convergence tests with respect to supercell size or time step, or direct comparison of the simulated spin textures or Hall conductivity against existing experimental data on YMn₆Sn₆ are reported, leaving the uniformity of the scalar spin chirality and the resulting constant Berry curvature unvalidated."}],"tokens_in":1475,"tokens_out":445,"duration_ms":21969,"standing_objections":[]},"desk_editor":{"model":"grok-4.3","letter":"The central result is a computational prediction that YMn6Sn6 hosts a topological Hall plateau between -0.5 and 0.5 T. The plateau comes from nearly constant real-space Berry curvature tied to uniform scalar spin chirality in a disordered skyrmion phase that the authors say is stabilized by planar DMI plus ferromagnetic exchange. The response is antisymmetric in field, and its magnitude and sign depend on Hund's coupling and chemical potential through Dirac points and van Hove singularities. They also report topological magnons in the same phase.\n\nThe work combines DFT with spin-dynamics simulations to generate the textures and then computes the Hall response from those textures. That workflow is standard but applied here to a specific quasi-2D kagome material, and the link between the disordered skyrmion state and the plateau is presented as new for this compound.\n\nThe main limitation is the absence of the actual numbers. The abstract gives no DMI vector components, no exchange constants, no temperature, no supercell size, and no damping or field-sweep protocol. The uniformity of the chirality across the field range is the load-bearing step; without those parameters or any convergence tests it is not possible to judge whether the phase survives or whether the plateau is robust. The stress-test concern about the planar DMI assumption therefore stands on the evidence supplied.\n\nThis is a materials-prediction paper aimed at researchers working on topological transport in kagome magnets or skyrmion-related Hall effects. Someone in that niche could extract a concrete, testable claim if the methods section supplies the missing parameters.\n\nThe thinking is coherent on its own terms and the citation pattern looks ordinary for the field. The paper deserves peer review so that referees can examine the spin-dynamics implementation and the numerical stability of the reported phase.","headline":"The paper predicts a topological Hall plateau in YMn6Sn6 from a disordered skyrmion phase with uniform chirality, but the simulation parameters and checks are missing so the claim rests on unshown details.","tokens_in":2451,"tokens_out":455,"would_cite":false,"duration_ms":24714,"reading_group":"maybe","serious_thinker":"yes","would_accept_peer_review":true},"rs_alignment":null,"lean_confirmation":null,"pith_extraction":{"msc":[],"pacs":[],"model":"grok-4.3","headline":"Disordered skyrmions in YMn6Sn6 generate a topological Hall plateau for fields below 0.5 T.","keywords":["topological Hall effect","disordered skyrmions","kagome magnet","Dzyaloshinskii-Moriya interaction","Berry curvature","scalar spin chirality","YMn6Sn6","topological magnons"],"falsifier":"Experimental measurement showing no Hall resistivity plateau or spatially varying Berry curvature in YMn6Sn6 for fields below 0.5 T would falsify the proposed mechanism.","tokens_in":2639,"feed_emoji":"🧲","tokens_out":739,"duration_ms":24199,"temperature":0.7,"pith_summary":"The paper examines how Dzyaloshinskii-Moriya interaction shapes spin textures in the quasi-2D kagome magnet YMn6Sn6. A mainly planar DMI combined with ferromagnetic exchange stabilizes a disordered skyrmion phase that survives at low external fields. This phase produces a topological Hall plateau between -0.5 and 0.5 T because nearly uniform scalar spin chirality creates constant real-space Berry curvature. The plateau magnitude and sign depend on Hund's coupling strength and chemical potential near Dirac points and van Hove singularities. The work also finds topological magnon excitations in the same phase.","feed_headline":"Disordered skyrmions produce Hall plateau in YMn6Sn6 below 0.5 T","feed_subtitle":"Uniform scalar spin chirality creates constant Berry curvature, with response set by Hund coupling and chemical potential near Dirac points.","key_machinery":"The disordered skyrmion phase stabilized by predominantly planar DMI and ferromagnetic exchange, which produces nearly uniform scalar spin chirality and constant real-space Berry curvature.","core_discovery":"Within an ab initio framework combining density functional theory and spin-dynamics simulations, realistic spin textures show a disordered skyrmion phase in YMn6Sn6 that persists for Bext < 0.5 T, with skyrmion size decreasing as the field increases. This phase exhibits a topological Hall plateau in the range −0.5 ≤ Bext < 0.5 T driven by nearly uniform scalar spin chirality and the resulting constant real-space Berry curvature. The response is antisymmetric with magnetic field while its magnitude and sign are determined by the interplay between Hund's coupling strength and chemical potential, signifying the role of Dirac points and van Hove singularities. Topological magnon excitations also","pith_inferences":["Doping experiments that shift chemical potential could switch the sign of the Hall plateau.","Similar kagome magnets with planar DMI may host comparable skyrmion phases at accessible fields.","Constant Berry curvature from uniform chirality could support robust topological transport if the phase remains stable at higher temperatures.","Magnon spectroscopy on the material could test the predicted topological magnon modes."],"forward_implications":["The topological Hall response is antisymmetric with magnetic field.","Magnitude and sign of the plateau are set by Hund's coupling strength and chemical potential.","Dirac points and van Hove singularities influence the Hall response.","Topological magnon excitations exist in the disordered skyrmion phase."],"fun_headline_variants":["Disordered skyrmions produce Hall plateau in YMn6Sn6","Topological Hall plateau in YMn6Sn6 from skyrmions","Skyrmion disorder produces Hall plateau in YMn6Sn6","Disordered skyrmions produce topological Hall plateau in YMn6Sn6"],"cache_read_input_tokens":2112,"weakest_assumption_plain":"A predominantly planar DMI together with ferromagnetic exchange stabilizes a disordered skyrmion phase that persists for Bext < 0.5 T.","fun_headline_variants_meta":{"raw":{"variants":["Disordered skyrmions produce Hall plateau in YMn6Sn6","Topological Hall plateau in YMn6Sn6 from skyrmions","Skyrmion disorder produces Hall plateau in YMn6Sn6","Disordered skyrmions produce topological Hall plateau in YMn6Sn6"]},"model":"grok-4.3","cost_usd":0.010297,"raw_usage":{"total_tokens":4597,"prompt_tokens":741,"num_sources_used":0,"completion_tokens":77,"cost_in_usd_ticks":102974500,"prompt_tokens_details":{"text_tokens":741,"audio_tokens":0,"image_tokens":0,"cached_tokens":256},"completion_tokens_details":{"audio_tokens":0,"reasoning_tokens":3779,"accepted_prediction_tokens":0,"rejected_prediction_tokens":0}},"tokens_in":741,"tokens_out":77,"duration_ms":35927,"temperature":1.0,"reasoning_tokens":3779,"cache_read_input_tokens":256,"cache_creation_input_tokens":0},"cache_creation_input_tokens":0},"created_at":"2026-07-02T18:42:12.271589+00:00","model_set":{"reader":"grok-4.3"},"falsifier":"Experimental measurement showing no Hall resistivity plateau or spatially varying Berry curvature in YMn6Sn6 for fields below 0.5 T would falsify the proposed mechanism.","supporting_citations":[],"review_version":1}