{"id":"31b783d9-65c0-4818-b493-3e573a98e226","arxiv_id":"2605.30074","paper_version":1,"verdict":"UNVERDICTED","confidence":"LOW","novelty_score":6.0,"correctness_risk":"unknown","formal_verification":"none","parameter_count":0,"one_line_summary":"Band-selective Kondo coupling on specific Fermi pockets generates the anisotropic exchange that explains q1D FM excitations in CeSb2.","lead":"ARPES on CeSb2 finds no spin-density-wave gap on Fermi pockets but selective Ce 4f weight on C2-aligned pockets. This suggests band-selective Kondo coupling creates the anisotropic exchange behind its quasi-one-dimensional ferromagnetic excitations.","discovery_kind":"new_application","skeptic_critique":{"model":"grok-4.3","headline":"Selective Ce 4f ARPES enhancement interpreted as band-selective Kondo without controls for matrix-element or hybridization alternatives","rationale":"The reader's weakest_assumption exactly isolates the interpretive leap from resonant intensity to Kondo mechanism. The provided abstract text contains no additional data that would secure this step, so the provisional UNVERDICTED status is unaffected.","tokens_in":1705,"tokens_out":317,"duration_ms":13468,"concrete_test":"Acquire resonant ARPES maps at the Ce 4f edge with both s- and p-polarized light (or at photon energies detuned 5–10 eV below resonance) on the same C2 pockets; if the selective enhancement ratio between C2 and other pockets changes by >30 % or reverses sign, matrix-element effects dominate the reported contrast.","verdict_should_be":"UNCHANGED","load_bearing_attack":"The central claim requires that the observed C2-pocket-selective Ce 4f intensity increase in resonant ARPES directly indicates band-selective Kondo coupling generating anisotropic exchange. Resonant ARPES cross-sections are known to vary strongly with orbital symmetry, k-point, and photon polarization via dipole matrix elements; momentum-dependent hybridization strengths can also produce intensity contrasts without invoking Kondo screening. The abstract reports the selectivity and the absence of an SDW gap but supplies no polarization dependence, off-resonance comparison, or matrix-element calculation to discriminate Kondo from these alternatives. Consequently the step from intensity map to anisotropic J (and thus to q1D FM excitations) rests on an untested causal attribution.","agreement_with_reader":"agree"},"referee_report":{"model":"grok-4.3","summary":"The manuscript claims that high-resolution ARPES on CeSb2 shows no spin-density-wave gap on the dispersive Fermi pockets, ruling out a nesting-driven origin for the q1D ferromagnetic excitations. Resonant ARPES instead reveals selective enhancement of Ce 4f spectral weight on the C2-distributed Fermi pockets aligned with the Ce ladder; this is interpreted as band-selective Kondo coupling that produces strongly anisotropic magnetic exchange interactions, naturally explaining both the q1D FM excitations and the competing magnetic orders.","tokens_in":1830,"tokens_out":280,"duration_ms":18902,"significance":"If the causal link from selective intensity to band-selective Kondo coupling holds, the result supplies an electronic mechanism for emergent low-dimensional magnetism in correlated f-electron systems without requiring nesting, with potential relevance to other candidate spin-triplet superconductors.","major_comments":[{"comment":"Abstract: the central claim that the observed C2-pocket-selective Ce 4f intensity increase 'signifies band-selective Kondo coupling' is load-bearing for the proposed mechanism, yet the manuscript supplies no polarization-dependent data, off-resonance comparison, or matrix-element calculation to discriminate this from known alternatives (dipole matrix elements varying with orbital symmetry/k-point or momentum-dependent hybridization strengths).","section":"Abstract"}],"minor_comments":[],"recommendation":"major_revision","confidential_remarks":null},"author_rebuttal":{"model":"grok-4.3","summary":"We thank the referee for the careful reading and constructive feedback on our manuscript. We address the single major comment below and will revise the manuscript accordingly to strengthen the presentation of our interpretation.","responses":[{"response":"We appreciate the referee identifying this point. The resonant ARPES enhancement occurs specifically at the Ce 4f resonance energy and is confined to the C2 pockets that align with the real-space Ce ladder direction; this momentum-space pattern, together with the lack of an SDW gap on the dispersive pockets, forms the basis for interpreting the data as evidence of band-selective Kondo coupling. We acknowledge, however, that the manuscript does not contain polarization-dependent ARPES, explicit off-resonance comparisons, or matrix-element calculations that would quantitatively exclude orbital-symmetry or hybridization-induced intensity variations. In the revised manuscript we will (i) change the abstract wording from 'signifies' to 'is consistent with' band-selective Kondo coupling, (ii) add a dedicated paragraph in the discussion that addresses possible matrix-element contributions and explains why the observed selectivity tracks the Ce-ladder geometry rather than generic k-dependent matrix elements, and (iii) include any available off-resonance spectra for direct comparison. These changes will make the evidential basis explicit without overstating the current data.","revision_made":"partial","referee_comment":"[Abstract] Abstract: the central claim that the observed C2-pocket-selective Ce 4f intensity increase 'signifies band-selective Kondo coupling' is load-bearing for the proposed mechanism, yet the manuscript supplies no polarization-dependent data, off-resonance comparison, or matrix-element calculation to discriminate this from known alternatives (dipole matrix elements varying with orbital symmetry/k-point or momentum-dependent hybridization strengths)."}],"tokens_in":1223,"tokens_out":370,"duration_ms":21856,"standing_objections":[]},"desk_editor":{"model":"grok-4.3","letter":"The paper's main contribution is an ARPES-based argument that the q1D ferromagnetic excitations in CeSb2 arise from band-selective Kondo coupling rather than Fermi-surface nesting. High-resolution data find no spin-density-wave gap on the dispersive pockets, which undercuts the nesting scenario. Resonant ARPES then shows stronger Ce 4f spectral weight on the C2-distributed pockets that align with the Ce ladder, and the authors interpret this selectivity as the source of anisotropic exchange that can explain both the excitations and the competing orders.\n\nThe no-gap observation is useful and directly addresses one proposed mechanism. The selective enhancement is a clear experimental result worth reporting. The work stays within the existing literature on CeSb2 and f-electron systems without overclaiming.\n\nThe soft spot is the causal step from intensity contrast to Kondo coupling. Resonant ARPES intensities are known to depend on dipole matrix elements that change with orbital character, momentum, and polarization; momentum-dependent hybridization can also produce pocket-selective weight without Kondo screening. The abstract and description give no polarization dependence, off-resonance comparison, or matrix-element calculation to separate these effects. Without those checks the link to anisotropic J remains an inference.\n\nThis is for researchers working on f-electron magnetism and spin-triplet candidates who already know the material. The data are worth referee scrutiny even if the interpretation needs tightening. I would send it for peer review.","headline":"ARPES shows no SDW gap and selective 4f weight on C2 pockets, but the Kondo-coupling attribution lacks matrix-element controls.","tokens_in":2359,"tokens_out":355,"would_cite":false,"duration_ms":16352,"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":"Band-selective Kondo coupling generates the quasi-one-dimensional ferromagnetic excitations in CeSb2.","keywords":["CeSb2","resonant ARPES","band-selective Kondo coupling","quasi-one-dimensional ferromagnetic excitations","spin-triplet superconductor","f-electron systems","anisotropic magnetic exchange","competing magnetic orders"],"falsifier":"Observation of a spin-density-wave gap on the dispersive Fermi pockets, or a demonstration that matrix-element calculations reproduce the 4f intensity pattern without Kondo coupling, would falsify the mechanism.","tokens_in":2610,"feed_emoji":"🧲","tokens_out":704,"duration_ms":20542,"temperature":0.7,"pith_summary":"The paper examines why quasi-one-dimensional ferromagnetic excitations appear in the candidate spin-triplet superconductor CeSb2 despite its quasi-two-dimensional lattice. High-resolution ARPES finds no spin-density-wave gap on the dispersive Fermi pockets, which disfavors a nesting mechanism. Resonant ARPES instead detects strong selective enhancement of Ce 4f spectral weight specifically on the C2-distributed Fermi pockets that align with the Ce ladder. This pattern indicates band-selective Kondo coupling, which in turn produces strongly anisotropic magnetic exchange interactions. The resulting anisotropy accounts for both the observed ferromagnetic excitations and the competing magnetic orders in this f-electron material.","feed_headline":"Kondo coupling drives one-dimensional magnetism in CeSb2","feed_subtitle":"Resonant ARPES finds selective 4f weight on ladder-aligned pockets, generating anisotropic exchange that explains the excitations without ne","key_machinery":"Band-selective Kondo coupling identified via selective Ce 4f spectral weight enhancement on C2-distributed Fermi pockets aligned with the Ce ladder, which produces anisotropic magnetic exchange interactions.","core_discovery":"High-resolution ARPES resolves no spin-density-wave gap on the dispersive Fermi pockets, disfavoring a nesting-driven mechanism for the q1D FM excitations. Instead, resonant ARPES reveals a pronounced selective enhancement of Ce 4f spectral weight on the C2-distributed Fermi pockets aligned with the Ce ladder. This observation signifies band-selective Kondo coupling that generates strongly anisotropic magnetic exchange interactions, which can naturally account for both the q1D ferromagnetic excitations and the competing magnetic orders.","pith_inferences":["The selectivity may extend to other Ce-based ladder compounds and could be tuned by doping or pressure.","Anisotropic exchange fluctuations from this coupling might help stabilize the spin-triplet superconducting state.","Direct comparison of ARPES intensity with matrix-element simulations on the same pockets would test the Kondo interpretation.","Temperature-dependent ARPES could reveal how the selective 4f weight evolves near magnetic ordering temperatures."],"forward_implications":["Absence of an SDW gap rules out nesting as the driver of the q1D excitations.","Selective 4f enhancement on ladder-aligned pockets signals band-selective Kondo coupling.","The coupling produces strongly anisotropic magnetic exchange interactions.","Anisotropic exchange accounts for both the q1D ferromagnetic excitations and competing magnetic orders.","The same mechanism can explain emergent low-dimensional magnetism in other correlated f-electron systems."],"fun_headline_variants":["Band-selective Kondo coupling accounts for q1D magnetism in CeSb2","No nesting mechanism but Kondo for CeSb2 q1D FM excitations","Selective Ce 4f weight explains anisotropic exchange in CeSb2","Band selective Kondo as electronic origin in CeSb2"],"cache_read_input_tokens":2112,"weakest_assumption_plain":"The selective enhancement of Ce 4f spectral weight is caused by band-selective Kondo coupling rather than photoemission matrix-element effects or differing hybridization strengths.","fun_headline_variants_meta":{"raw":{"variants":["Band-selective Kondo coupling accounts for q1D magnetism in CeSb2","No nesting mechanism but Kondo for CeSb2 q1D FM excitations","Selective Ce 4f weight explains anisotropic exchange in CeSb2","Band selective Kondo as electronic origin in CeSb2"]},"model":"grok-4.3","cost_usd":0.011495,"raw_usage":{"total_tokens":4945,"prompt_tokens":640,"num_sources_used":0,"completion_tokens":65,"cost_in_usd_ticks":114953000,"prompt_tokens_details":{"text_tokens":640,"audio_tokens":0,"image_tokens":0,"cached_tokens":64},"completion_tokens_details":{"audio_tokens":0,"reasoning_tokens":4240,"accepted_prediction_tokens":0,"rejected_prediction_tokens":0}},"tokens_in":640,"tokens_out":65,"duration_ms":29879,"temperature":1.0,"reasoning_tokens":4240,"cache_read_input_tokens":64,"cache_creation_input_tokens":0},"cache_creation_input_tokens":0},"created_at":"2026-06-29T05:45:32.364445+00:00","model_set":{"reader":"grok-4.3"},"falsifier":"Observation of a spin-density-wave gap on the dispersive Fermi pockets, or a demonstration that matrix-element calculations reproduce the 4f intensity pattern without Kondo coupling, would falsify the mechanism.","supporting_citations":[],"review_version":1}