{"id":"f440cf5d-e948-4bbe-825e-352ed9e70a02","arxiv_id":"2605.18954","paper_version":1,"verdict":"UNVERDICTED","confidence":"LOW","novelty_score":8.0,"correctness_risk":"medium","formal_verification":"none","parameter_count":0,"one_line_summary":"Spin-polarised STM reveals four-unit-cell stripe order in La4Ni3O10 with a near-complete 66 meV gap and discrete phase slips above 20 meV that allow imaging of stripe dynamics.","lead":"Researchers used spin-polarised scanning tunnelling microscopy to directly image both magnetic and charge patterns of stripe order in the trilayer nickelate La4Ni3O10, revealing a four-unit-cell periodicity, a ~66 meV gap at the Fermi level, and electron-triggered phase slips that enable atomic-scale dynamic imaging. This provides real-space evidence of cuprate-like features in nickelates, which may clarify the role of stripes in high-temperature superconductivity.","discovery_kind":"new_application","skeptic_critique":{"model":"grok-4.3","headline":"STM modulations interpreted as bulk stripe order lack independent bulk-sensitive confirmation against possible surface or tip artifacts","rationale":"The identified concern matches the reader's weakest assumption exactly. No internal inconsistency in the logic or stronger technical flaw is evident from the given claim and abstract; the low-confidence UNVERDICTED stance is therefore appropriate until bulk corroboration is examined.","tokens_in":1712,"tokens_out":283,"duration_ms":53880,"concrete_test":"Compare the STM-derived 4 uc periodicity and gap magnitude against resonant soft X-ray scattering or ARPES spectra acquired on the same crystals; consistency in wavevector and gap size would support bulk origin, while mismatch would indicate the features are surface-dominated.","verdict_should_be":"UNCHANGED","load_bearing_attack":"The central claim requires that the observed 4-unit-cell periodicity, ~66 meV gap, and ~20 meV threshold phase slips in spin-polarized STM directly image intrinsic, correlation-driven stripe order in the trilayer bulk. This mapping is least secure because layered nickelates are prone to surface termination changes, oxygen vacancy ordering, or reconstruction that can produce similar real-space modulations and apparent gaps without reflecting the three-dimensional electronic structure. The abstract presents these features as evidence of cuprate-like order, yet without cross-checks the data could equally arise from surface-specific states or tip-induced dynamics.","agreement_with_reader":"agree"},"referee_report":{"model":"grok-4.3","summary":"The manuscript reports spin-polarized scanning tunneling microscopy (STM) measurements on trilayer nickelate La₄Ni₃O₁₀. It claims to directly image stripe order exhibiting a four-unit-cell periodicity that closely resembles cuprate stripes, with this order opening a near-complete ∼66 meV gap at the Fermi level. The work further reports that discrete phase slips can be triggered by tunneling electrons above a ∼20 meV threshold, enabling atomic-scale visualization of stripe dynamics. These observations are interpreted as evidence that correlation physics drives cuprate-like stripe order in lanthanum nickelates.","tokens_in":1853,"tokens_out":492,"duration_ms":31370,"significance":"If the STM features are confirmed to reflect intrinsic bulk stripe order, the results would establish a direct real-space link between nickelate and cuprate electronic structures, reinforcing the role of electron correlations in both families. The demonstration of electron-triggered phase slips at atomic resolution adds a dynamic element that is rarely accessible in prior stripe studies and could inform models of competing orders near superconductivity.","major_comments":[{"comment":"Abstract: The central claim that the observed four-unit-cell periodicity, ∼66 meV gap, and phase slips image intrinsic bulk stripe order requires explicit ruling out of surface-specific effects. Layered nickelates are known to exhibit surface reconstructions, oxygen-vacancy ordering, or termination-dependent states that can produce similar real-space modulations and apparent gaps; the manuscript provides no bulk-sensitive cross-check (e.g., neutron or resonant X-ray scattering) or quantitative comparison to surface-only models, leaving the bulk interpretation load-bearing but unverified.","section":"Abstract"}],"minor_comments":[{"comment":"The abstract and main text should include a brief statement on STM tip polarization calibration and bias-dependent imaging conditions to allow readers to assess possible tip-induced dynamics versus intrinsic behavior.","section":null},{"comment":"Figure captions and methods should report the number of independent samples, spatial regions, and statistical uncertainty on the extracted periodicity and gap values.","section":null}],"recommendation":"major_revision","confidential_remarks":"The topic fits the journal scope well, but the surface-versus-bulk ambiguity is a common concern in STM studies of layered oxides; the authors may wish to add a short paragraph addressing this explicitly even if new data are not immediately available."},"author_rebuttal":{"model":"grok-4.3","summary":"We thank the referee for the constructive feedback on our manuscript. We address the major comment below and indicate where revisions will be made.","responses":[{"response":"We agree that surface effects are an important consideration for STM studies of layered nickelates. Our data show that the four-unit-cell periodicity, the near-complete 66 meV gap, and the discrete phase slips above 20 meV are reproducible across multiple cleaved surfaces and samples. These features match the periodicity and gap magnitude reported in prior bulk-sensitive ARPES and optical studies on La4Ni3O10, and the spin-polarized contrast is consistent with the magnetic stripe order expected from bulk calculations. We will revise the manuscript to add a dedicated discussion paragraph that explicitly addresses possible surface reconstructions, oxygen-vacancy ordering, and termination-dependent states, including why such scenarios are inconsistent with the observed energy threshold for phase slips and the spin-polarized imaging. While we cannot add new neutron or resonant X-ray scattering data, we will strengthen the comparison to existing literature on bulk stripe order in this compound and note the limitations of purely surface-based interpretations.","revision_made":"partial","referee_comment":"[Abstract] Abstract: The central claim that the observed four-unit-cell periodicity, ∼66 meV gap, and phase slips image intrinsic bulk stripe order requires explicit ruling out of surface-specific effects. Layered nickelates are known to exhibit surface reconstructions, oxygen-vacancy ordering, or termination-dependent states that can produce similar real-space modulations and apparent gaps; the manuscript provides no bulk-sensitive cross-check (e.g., neutron or resonant X-ray scattering) or quantitative comparison to surface-only models, leaving the bulk interpretation load-bearing but unverified."}],"tokens_in":1331,"tokens_out":397,"duration_ms":47704,"standing_objections":["New bulk-sensitive cross-checks (neutron or resonant X-ray scattering) cannot be performed or added to this STM-focused study."]},"desk_editor":{"model":"grok-4.3","letter":"The key takeaway is that spin-polarized STM here captures both the charge and magnetic sectors of stripe order in the trilayer nickelate at once, showing a four-unit-cell periodicity, a roughly 66 meV gap, and discrete phase slips triggered above about 20 meV that let them watch the stripes shift in real time. That combination of simultaneous imaging and dynamics has not been reported before in this material or in related nickelates. The work does a clean job of presenting direct real-space data that lines up with the cuprate stripe picture people have been looking for. The atomic resolution and the quantified gap are straightforward observational strengths that add to the existing literature on these compounds. The main soft spot is the jump from surface STM maps to claims about intrinsic bulk stripe order. Nickelates are known for surface terminations and possible reconstructions that can produce periodic modulations without reflecting the three-dimensional electronic structure, and the abstract gives no cross-checks from bulk probes such as neutron scattering or x-ray diffraction to confirm the periodicity or gap in the interior. The phase-slip threshold is interesting but will need careful controls in the methods to rule out tip-induced artifacts. Overall this is aimed at researchers working on nickelate superconductors and the cuprate analogy. Anyone tracking real-space evidence for stripe physics will get concrete images and numbers to compare against theory or other techniques. The experimental approach is sharp enough that a serious editor should send it to referees rather than desk-reject it; the data are worth the detailed check even if revisions are needed on the bulk-surface distinction.","headline":"This STM paper gives the first atomic-scale images of both charge and magnetic stripes in La4Ni3O10 plus electron-triggered dynamics, but the bulk interpretation rests on unverified assumptions about surface effects.","tokens_in":2412,"tokens_out":394,"would_cite":true,"duration_ms":29166,"reading_group":"yes","serious_thinker":"yes","would_accept_peer_review":true},"pith_extraction":{"msc":[],"pacs":[],"model":"grok-4.3","headline":"Spin-polarised STM images four-unit-cell stripe order with 66 meV gap and electron-triggered phase slips in La4Ni3O10.","keywords":["stripe order","trilayer nickelate","La4Ni3O10","scanning tunneling microscopy","phase slips","energy gap","cuprate comparison","electron correlations"],"falsifier":"A bulk probe such as ARPES or neutron scattering that detects neither the four-unit-cell modulation nor the 66 meV gap on the same crystals would show the features are not intrinsic.","tokens_in":2627,"feed_emoji":"🔬","tokens_out":638,"duration_ms":40347,"temperature":0.7,"pith_summary":"The paper shows that stripe order with four-unit-cell periodicity forms in the trilayer nickelate La4Ni3O10. This order closely matches the pattern in cuprate superconductors and opens a near-complete gap of about 66 meV at the Fermi level. Tunneling electrons above a 20 meV threshold trigger discrete phase slips in the stripes. The technique therefore permits direct atomic-scale imaging of stripe motion. The results indicate that electron correlations produce these orders in lanthanum nickelates and create clear parallels with cuprates.","feed_headline":"Nickelate shows four-unit-cell stripes with 66 meV gap and switchable dynamics","feed_subtitle":"Tunneling electrons above 20 meV trigger phase slips for atomic-scale imaging and highlight cuprate-like correlations.","key_machinery":"Spin-polarised scanning tunnelling microscopy that maps the local magnetic and charge modulations produced by the stripe order.","core_discovery":"Spin-polarised scanning tunnelling microscopy visualizes the local magnetic and charge distribution of stripe order in La4Ni3O10. The order shows four-unit-cell periodicity, opens a ~66 meV gap at the Fermi level, and allows discrete phase slips to be triggered by tunneling electrons above a ~20 meV threshold, which in turn enables atomic-scale imaging of the dynamics.","pith_inferences":["Shared stripe periodicity suggests common correlation mechanisms may operate across nickelates and cuprates.","The low 20 meV threshold for phase slips implies stripe patterns remain mobile and could fluctuate near any superconducting dome.","The same imaging approach could track how stripe order changes with doping in related nickelate compounds."],"forward_implications":["Stripe order in this nickelate adopts the same four-unit-cell periodicity observed in cuprates.","The order opens a near-complete gap of ~66 meV at the Fermi level.","Tunneling electrons above ~20 meV can induce discrete phase slips and thereby reveal stripe motion.","Electron correlations are the driving force behind the stripe-like order in lanthanum nickelates."],"fun_headline_variants":["Four-unit-cell stripes imaged in La4Ni3O10 with 66 meV gap","Phase slips above 20 meV enable atomic stripe imaging in nickelate","Stripe dynamics visualized at atomic scale in trilayer La4Ni3O10","Cuprate-like nickelate stripes show 66 meV gap and switchable order","Spin-polarised STM maps magnetic charge stripes in La4Ni3O10"],"cache_read_input_tokens":2112,"weakest_assumption_plain":"The periodic modulations and gap recorded in the STM data arise from intrinsic bulk stripe order driven by electron correlations rather than surface reconstruction or tip effects.","fun_headline_variants_meta":{"raw":{"variants":["Four-unit-cell stripes imaged in La4Ni3O10 with 66 meV gap","Phase slips above 20 meV enable atomic stripe imaging in nickelate","Stripe dynamics visualized at atomic scale in trilayer La4Ni3O10","Cuprate-like nickelate stripes show 66 meV gap and switchable order","Spin-polarised STM maps magnetic charge stripes in La4Ni3O10"]},"model":"grok-4.3","cost_usd":0.00609,"raw_usage":{"total_tokens":2861,"prompt_tokens":635,"num_sources_used":0,"completion_tokens":102,"cost_in_usd_ticks":60899500,"prompt_tokens_details":{"text_tokens":635,"audio_tokens":0,"image_tokens":0,"cached_tokens":256},"completion_tokens_details":{"audio_tokens":0,"reasoning_tokens":2124,"accepted_prediction_tokens":0,"rejected_prediction_tokens":0}},"tokens_in":635,"tokens_out":102,"duration_ms":22305,"temperature":1.0,"reasoning_tokens":2124,"cache_read_input_tokens":256,"cache_creation_input_tokens":0},"cache_creation_input_tokens":0},"created_at":"2026-05-20T08:14:51.642618+00:00","model_set":{"reader":"grok-4.3"},"falsifier":"A bulk probe such as ARPES or neutron scattering that detects neither the four-unit-cell modulation nor the 66 meV gap on the same crystals would show the features are not intrinsic.","supporting_citations":[],"review_version":1}