{"id":"ae9d9fc0-922f-40d8-a2e9-f8aa93fecf42","arxiv_id":"2607.05912","paper_version":1,"verdict":"UNVERDICTED","confidence":"LOW","novelty_score":6.0,"correctness_risk":"unknown","formal_verification":"none","parameter_count":2,"one_line_summary":"Interfacial noncollinear spin-orbit filtering converts hidden bulk spin-Hall textures into unconventional emitted spin currents, enabling out-of-plane polarization from high-symmetry sources.","lead":"The paper argues that spin currents leaving a high-symmetry bulk crystal can still carry unconventional polarization because a low-symmetry interfacial spin-orbit field filters which bulk spin textures get transmitted. If correct, this would let engineers reprogram spin polarization in ordinary CMOS-compatible spin-Hall materials without exotic low-symmetry crystals.","discovery_kind":"new_method","skeptic_critique":{"model":"grok-4.5","headline":"The claim that high-symmetry bulk sources emit sizable unconventional spin currents rests on an interfacial SOC field that is low-symmetry, noncollinear, and strong enough to filter hidden textures without being erased by realistic interface disorder.","rationale":"The reader correctly isolated the interfacial SOC premise as the weakest link and correctly withheld a verdict for lack of equations, parameters, and data. The full abstract confirms that the paper’s positive evidence is model-based (“rotationally symmetric minimal model” and “realistic high-symmetry Dirac-semimetal model”) rather than experimental, so the same premise remains load-bearing once the models are examined: the models can demonstrate the filtering channel only by choosing an interface Hamiltonian that already satisfies the three conditions above. That choice is not free; it must be shown to be robust under realistic interface disorder and to produce currents of practical magnitude. Because the abstract supplies no such robustness check or experimental interface control, the appropriate adjustment is from UNVERDICTED to CONDITIONAL: the conceptual mechanism is coherent and the bulk–interface hybrid framing is useful, but acceptance of the device claim requires the concrete disorder/SOC sweep (or an equivalent experimental interface series) to confirm that the unconventional component survives. No internal inconsistency is alleged; the concern is solely whether the key physical ingredient is present at the strength the models assume. Agreement with the reader is therefore full on the identity of the load-bearing assumption; the only change is to move the verdict one step toward conditional acceptance once the models are acknowledged to exist.","tokens_in":2145,"tokens_out":780,"duration_ms":35711,"concrete_test":"In the Dirac-semimetal (or minimal) model, compute the ratio of out-of-plane to conventional emitted spin current while sweeping interfacial SOC strength α_R (or equivalent) and a controlled disorder potential (Anderson or alloy scattering) at fixed bulk parameters; if the unconventional component remains >10–20 % of the conventional one only for α_R larger than typical experimental interface values (~0.1–1 eV·Å) or collapses once the elastic mean free path approaches the interface coherence length, the device-relevance claim weakens and the filtering mechanism is model-limited.","verdict_should_be":"CONDITIONAL","load_bearing_attack":"The central construction treats emitted spin current as a bulk–interface hybrid: bulk supplies momentum-resolved spin-Hall textures that average to a conventional polarization, while a low-symmetry interfacial spin-orbit field (noncollinear with those textures) imposes spin-dependent transmission that converts the hidden components into an observable out-of-plane emitted current. For this to be device-relevant rather than a model artifact, the interface Hamiltonian must (i) break the residual rotational/mirror symmetries that still constrain the bulk average, (ii) remain noncollinear with the incident spin texture over the relevant Fermi surface, and (iii) produce a transmission contrast large enough that the unconventional component is not washed out by interface roughness, interdiffusion, or alloy disorder. The abstract asserts that such a field is “generally” present at realistic heterostructure interfaces and that both a rotationally symmetric minimal model and a Dirac-semimetal model already yield “sizable” out-of-plane currents. That assertion is the single load-bearing premise: if the interface SOC is collinear, weak, or disordered on the scale of the mean free path, the filtering channel closes and the emitted polarization reverts to the bulk-symmetry-allowed value. Nothing in the abstract (or the reader’s material) quantifies the required SOC strength, the angular misalignment, or the disorder tolerance, so the leap from “possible in clean models” to “available in CMOS-compatible stacks” remains unsecured.","agreement_with_reader":"agree"},"referee_report":{"model":"grok-4.5","summary":"The manuscript argues that the device-relevant quantity in spin-Hall heterostructures is not the fully symmetry-averaged bulk spin Hall current but the emitted spin current transmitted across the interface, and therefore treats emitted spin currents as bulk–interface hybrid responses. It proposes interfacial noncollinear filtering: a low-symmetry interfacial spin-orbit field, generally noncollinear with the momentum-resolved bulk spin polarization, imposes spin-dependent transmission that converts hidden bulk spin-Hall texture components into an observable unconventional (out-of-plane) emitted spin current. Using a rotationally symmetric minimal model and a realistic high-symmetry Dirac-semimetal model, the authors report that conventional spin Hall sources can emit sizable out-of-plane spin currents when those hidden textures are selectively transmitted by the interfacial field, offering a route to reprogram spin-current polarization without low-symmetry bulk crystals or external symmetry breaking.","tokens_in":2422,"tokens_out":1090,"duration_ms":41018,"significance":"If the filtering mechanism is robust under realistic interface conditions, the work would reframe spin-current polarization as a cooperative bulk–interface response and provide a practical strategy for generating unconventional spin polarizations in high-symmetry, CMOS-compatible spin-Hall materials. That is a meaningful conceptual and device-level contribution for spintronics. Credit is due for cleanly separating bulk spin-Hall textures (treated as inputs allowed by crystal symmetry, including hidden components) from the interfacial filter as a distinct physical ingredient, and for demonstrating the effect in both a minimal rotationally symmetric model and a material-motivated Dirac-semimetal model rather than only a single toy Hamiltonian.","major_comments":[{"comment":"The central device claim—that high-symmetry bulk sources emit sizable unconventional out-of-plane currents—rests on a low-symmetry interfacial spin-orbit field that is noncollinear with the incident momentum-resolved spin texture and strong enough to produce useful transmission contrast. The abstract asserts such a field is “generally” present at realistic heterostructure interfaces, but the manuscript must quantify the required field strength, angular misalignment, and resulting transmission contrast (e.g., thresholds or a phase diagram in the minimal model). Without those bounds it is unclear whether the reported “sizable” currents correspond to experimentally typical interface SOC scales or only to an optimistic clean-model regime.","section":null},{"comment":"Disorder, interdiffusion, alloy scattering, and interface roughness are expected to degrade spin-dependent transmission contrast. Because the filtering channel closes if the interfacial field is washed out on the scale of the mean free path, the emitted polarization would then revert to the bulk-symmetry-allowed value. The manuscript should address robustness of interfacial noncollinear filtering against realistic interface disorder—at least via a scattering or mean-free-path estimate—since this is load-bearing for the claim of device-relevant unconventional emission rather than a clean-model artifact.","section":null},{"comment":"For the realistic high-symmetry Dirac-semimetal model, the paper should make explicit which material parameters and interface crystallography are used, how the hidden bulk spin-Hall textures are obtained, and whether the out-of-plane emitted component remains sizable when the interface Hamiltonian is constrained by the actual residual symmetries of a plausible heterostructure stack (rather than an idealized low-symmetry filter imposed by hand). If the filter’s symmetry lowering is stronger than what a real epitaxial interface permits, the cross-model claim that conventional sources suffice needs to be qualified.","section":null}],"minor_comments":[{"comment":"Define “hidden” momentum-resolved spin-Hall components versus the fully symmetry-averaged bulk response early and with consistent notation, so that the bulk-input / interface-filter separation is unambiguous throughout.","section":null},{"comment":"Quantify “sizable” for the out-of-plane emitted current (e.g., as a fraction of the conventional in-plane component or in absolute units) in both models so that the device claim can be compared across figures and to experiment.","section":null},{"comment":"Clarify free parameters of the interfacial spin-orbit field (strength, orientation, range) and of each model Hamiltonian in a single place, and state which results are parameter-free consequences of the filtering mechanism versus which require tuning.","section":null},{"comment":"If experimental interface SOC scales or prior heterostructure measurements are cited as motivation for the “generally present” claim, make the comparison to the model parameters explicit rather than qualitative.","section":null}],"recommendation":"major_revision","confidential_remarks":"Fit for cond-mat.mes-hall is appropriate. The named mechanism “interfacial noncollinear filtering” is a packaging choice rather than an invented entity that creates circularity; the bulk-input / interface-filter separation is not definitionally circular. The load-bearing risk is physical realism of the interface SOC (strength, noncollinearity, disorder tolerance), not internal inconsistency of the hybrid-response construction. I would not reject on consensus grounds: disagreement with the bulk-only view of spin Hall polarization is the point of the paper and should be judged on whether the models and interface assumptions hold."},"author_rebuttal":{"model":"grok-4.5","summary":"We thank the Referee for a careful and constructive report that correctly identifies the conditions under which interfacial noncollinear filtering can be device-relevant. The three major points—quantitative bounds on interfacial field strength and misalignment, robustness against interface disorder, and fidelity of the Dirac-semimetal demonstration to residual symmetries of a realistic stack—are load-bearing for the central claim. We agree that the present manuscript does not address them with sufficient clarity or quantification. Below we respond point by point and describe the revisions we will implement. These changes will bound the “sizable” regime, qualify the disorder window, and make the material/symmetry content of the realistic model fully explicit, without altering the conceptual separation of bulk spin-Hall textures from the interfacial filter.","responses":[{"response":"We agree that the manuscript currently lacks systematic bounds on the interfacial field and that the word “generally” in the abstract is therefore under-supported. In the revision we will add a parameter study of the minimal rotationally symmetric model that maps the emitted out-of-plane spin current and the spin-dependent transmission contrast versus (i) interfacial SOC strength (relative to bulk hopping and Fermi energy) and (ii) the angular misalignment between the interfacial spin-orbit field and the momentum-resolved bulk spin polarization. The results will be presented as contour plots or a phase diagram that identifies the region in which the unconventional component becomes a sizable fraction of the conventional emitted current. We will also compare the required interfacial SOC scale with values reported for common metal/oxide and metal/semimetal interfaces so that readers can judge experimental accessibility. The abstract and main text will be reworded to replace the unqualified “generally” with a statement conditioned on these bounds.","revision_made":"yes","referee_comment":"The central device claim—that high-symmetry bulk sources emit sizable unconventional out-of-plane currents—rests on a low-symmetry interfacial spin-orbit field that is noncollinear with the incident momentum-resolved spin texture and strong enough to produce useful transmission contrast. The abstract asserts such a field is “generally” present at realistic heterostructure interfaces, but the manuscript must quantify the required field strength, angular misalignment, and resulting transmission contrast (e.g., thresholds or a phase diagram in the minimal model). Without those bounds it is unclear whether the reported “sizable” currents correspond to experimentally typical interface SOC scales or only to an optimistic clean-model regime."},{"response":"The Referee is correct that the present clean-interface treatment leaves open whether the filtering channel survives realistic disorder, and that this is load-bearing for any device claim. A full microscopic simulation of roughness, interdiffusion, and alloy scattering lies beyond the scope of this work. We will, however, add a dedicated discussion that supplies at least a scattering/mean-free-path estimate: we will introduce controlled lifetime broadening (or a simple transfer-matrix treatment with random interfacial potentials) and identify the regime in which the interfacial SOC energy remains larger than the disorder scale and the interface stays coherent over the relevant Fermi-wavelength length. We will state explicitly that strong interdiffusion or amorphous interfaces are expected to restore the bulk-symmetry-allowed polarization, so that the mechanism is most relevant to epitaxial or otherwise well-defined interfaces. This qualification will appear in the abstract, discussion, and conclusions so that the device claim is not overstated.","revision_made":"partial","referee_comment":"Disorder, interdiffusion, alloy scattering, and interface roughness are expected to degrade spin-dependent transmission contrast. Because the filtering channel closes if the interfacial field is washed out on the scale of the mean free path, the emitted polarization would then revert to the bulk-symmetry-allowed value. The manuscript should address robustness of interfacial noncollinear filtering against realistic interface disorder—at least via a scattering or mean-free-path estimate—since this is load-bearing for the claim of device-relevant unconventional emission rather than a clean-model artifact."},{"response":"We agree that the Dirac-semimetal section must be fully transparent about parameters, the origin of the hidden textures, and the residual symmetries of the interface. In the revision we will (i) list the concrete bulk Hamiltonian parameters and the material class they represent, (ii) document how the momentum-resolved bulk spin-Hall textures—including the hidden components—are obtained from the bulk response before any interface is introduced, and (iii) replace or supplement the hand-imposed low-symmetry filter with an interface Hamiltonian whose residual symmetries match those of a plausible epitaxial stack (e.g., a high-symmetry crystallographic face against a metal or insulator that preserves a subset of bulk mirrors/rotations while still permitting a noncollinear interfacial field). We will recompute the emitted out-of-plane current under that constrained interface. If the unconventional component is reduced but finite we will report the reduced magnitude; if it vanishes under the residual symmetries of the most natural stacks we will qualify the claim that conventional sources alone suffice and note that controlled interfacial symmetry lowering remains necessary. Either outcome will be stated clearly.","revision_made":"yes","referee_comment":"For the realistic high-symmetry Dirac-semimetal model, the paper should make explicit which material parameters and interface crystallography are used, how the hidden bulk spin-Hall textures are obtained, and whether the out-of-plane emitted component remains sizable when the interface Hamiltonian is constrained by the actual residual symmetries of a plausible heterostructure stack (rather than an idealized low-symmetry filter imposed by hand). If the filter’s symmetry lowering is stronger than what a real epitaxial interface permits, the cross-model claim that conventional sources suffice needs to be qualified."}],"tokens_in":1930,"tokens_out":1259,"duration_ms":50059,"standing_objections":["A quantitative, material-specific microscopic treatment of interface roughness, interdiffusion, and alloy scattering that would fully settle experimental transmission contrast is beyond the present theoretical scope; only estimates and qualitative bounds will be provided."]},"desk_editor":{"model":"grok-4.5","letter":"The one thing to know: this paper reframes the device-relevant spin current as a bulk–interface hybrid and argues that a low-symmetry interfacial spin-orbit field, noncollinear with the incident momentum-resolved spin texture, can filter hidden bulk components into a net out-of-plane emitted polarization. High-symmetry spin Hall sources then no longer need low-symmetry bulk crystals or external symmetry breaking to deliver unconventional spins.\n\nWhat is actually new is that framing and the filtering mechanism, not the bulk SHE or interfacial SOC themselves. They show the idea in a rotationally symmetric minimal model and a realistic high-symmetry Dirac-semimetal model, and claim sizable out-of-plane emission once the interface selects the hidden textures. That is the right theoretical level for a mechanism paper, and the logic is coherent: bulk supplies the momentum-resolved textures (including symmetry-hidden pieces that average to a conventional polarization); the interface supplies spin-dependent transmission that breaks the residual averaging. Circularity is not the problem—the bulk textures are inputs, the filter is a separate physical ingredient.\n\nThe soft spot is real but proportionate. The whole construction stands on an interfacial SOC field that is low-symmetry, noncollinear over the relevant Fermi surface, and strong enough that the unconventional component survives roughness, interdiffusion, and disorder. The abstract calls this “generally” present at realistic heterostructure interfaces. That is the load-bearing premise. Without numbers on required SOC strength, angular misalignment, and disorder tolerance, the jump from clean models to CMOS-compatible stacks is still unsecured. Free parameters in the interface Hamiltonian will decide whether “sizable” is robust or tuned. That is a referee-level gap, not a reason to dismiss the idea.\n\nWho it is for: spintronics and spin-orbitronics people who need out-of-plane or other unconventional polarizations from high-efficiency, high-symmetry sources. A serious referee should see it. I would send it to peer review; if the models and any interface estimates hold up under scrutiny, it is a useful design strategy. If the interface premise collapses under realistic disorder, the paper still clarifies why emitted current is not just bulk SHE.","headline":"Clean mechanism paper: interfacial noncollinear filtering can unlock unconventional emitted spins from high-symmetry bulk SHE sources, but the interface-SOC premise still needs quantitative teeth.","tokens_in":3127,"tokens_out":542,"would_cite":false,"duration_ms":23469,"reading_group":"maybe","serious_thinker":"yes","would_accept_peer_review":true},"rs_alignment":null,"lean_confirmation":null,"pith_extraction":{"msc":[],"pacs":["72.25.Dc","72.25.Mk","73.40.-c","75.70.Tj"],"model":"grok-4.5","headline":"Interfaces can filter hidden spin textures so ordinary spin-Hall sources emit out-of-plane spin currents","keywords":["spin Hall effect","emitted spin current","interfacial spin-orbit field","noncollinear filtering","out-of-plane spin polarization","heterostructure","Dirac semimetal","spin-orbit torque"],"falsifier":"Measure the out-of-plane spin polarization of the emitted current in a high-symmetry spin-Hall material (for example a Dirac-semimetal or ordinary heavy-metal stack) while deliberately varying interface chemistry or termination; the unconventional component should appear or vanish with the presence of the low-symmetry interfacial field, not with bulk crystal symmetry alone.","tokens_in":2996,"feed_emoji":"🔄","tokens_out":604,"duration_ms":10855,"temperature":0.7,"pith_summary":"Spin Hall currents are usually treated as bulk responses whose spin polarization is locked by crystal symmetry, which has driven a search for low-symmetry crystals when devices need unconventional (for example out-of-plane) spins. This paper argues that the quantity that actually reaches a device is not the bulk-averaged current but the spin current emitted across a realistic interface. At that interface a low-symmetry spin-orbit field is typically noncollinear with the momentum-resolved spin texture of the incident bulk Hall current; the mismatch acts as a spin-dependent filter that selectively transmits “hidden” polarization components that cancel under bulk averaging. The result is an unconventional emitted spin current even when the bulk crystal itself is high-symmetry. The authors demonstrate the mechanism with both a minimal rotationally symmetric model and a realistic Dirac-semimetal heterostructure, showing that conventional CMOS-compatible spin-Hall materials can emit sizable out-of-plane spins without low-symmetry bulk crystals or external symmetry breaking.","feed_headline":"Interfaces let ordinary spin-Hall sources emit out-of-plane spins","feed_subtitle":"A low-symmetry interfacial field filters hidden bulk textures into unconventional currents without exotic crystals.","key_machinery":"Interfacial noncollinear filtering: the mismatch between a low-symmetry interfacial spin-orbit field and the momentum-resolved bulk spin polarization produces spin-dependent transmission that converts symmetry-hidden bulk components into net unconventional emitted spin current.","core_discovery":"Emitted spin currents are bulk–interface hybrid responses. A low-symmetry interfacial spin-orbit field, noncollinear with the momentum-resolved bulk spin-Hall texture, filters hidden polarization components into an observable unconventional emitted spin current, so high-symmetry bulk sources can deliver sizable out-of-plane spins.","pith_inferences":[],"forward_implications":[],"fun_headline_variants":["Interfaces filter hidden bulk spin textures into out-of-plane currents","Noncollinear interfaces turn ordinary spin Hall into unconventional spins","High-symmetry sources emit out-of-plane spins via interfacial filtering","Bulk spin Hall currents yield out-of-plane polarization through interfaces","Interfacial fields filter spin Hall textures for unconventional currents"],"cache_read_input_tokens":2304,"weakest_assumption_plain":"Realistic interfaces must host a sufficiently strong, low-symmetry spin-orbit field that stays noncollinear with the bulk spin texture and is not washed out by disorder, interdiffusion, or reconstruction.","fun_headline_variants_meta":{"raw":{"variants":["Interfaces filter hidden bulk spin textures into out-of-plane currents","Noncollinear interfaces turn ordinary spin Hall into unconventional spins","High-symmetry sources emit out-of-plane spins via interfacial filtering","Bulk spin Hall currents yield out-of-plane polarization through interfaces","Interfacial fields filter spin Hall textures for unconventional currents"]},"model":"grok-4.5","cost_usd":0.01004,"raw_usage":{"total_tokens":2258,"prompt_tokens":781,"num_sources_used":0,"completion_tokens":89,"cost_in_usd_ticks":100400000,"prompt_tokens_details":{"text_tokens":781,"audio_tokens":0,"image_tokens":0,"cached_tokens":256},"completion_tokens_details":{"audio_tokens":0,"reasoning_tokens":1388,"accepted_prediction_tokens":0,"rejected_prediction_tokens":0}},"tokens_in":781,"tokens_out":89,"duration_ms":16804,"temperature":1.0,"reasoning_tokens":1388,"cache_read_input_tokens":256,"cache_creation_input_tokens":0},"cache_creation_input_tokens":0},"created_at":"2026-07-08T19:30:28.921519+00:00","model_set":{"reader":"grok-4.5"},"falsifier":"Measure the out-of-plane spin polarization of the emitted current in a high-symmetry spin-Hall material (for example a Dirac-semimetal or ordinary heavy-metal stack) while deliberately varying interface chemistry or termination; the unconventional component should appear or vanish with the presence of the low-symmetry interfacial field, not with bulk crystal symmetry alone.","supporting_citations":[],"review_version":1}