{"id":"5f7bdacd-c9b5-40e9-896a-696ba5afe8b6","arxiv_id":"2605.15981","paper_version":2,"verdict":"CONDITIONAL","confidence":"HIGH","novelty_score":6.0,"correctness_risk":"medium","formal_verification":"none","parameter_count":5,"one_line_summary":"A single-helix tight-binding model generates orbital angular momentum textures from chirality alone, yielding a finite orbital Edelstein response while the projected longitudinal orbital-current conductivity vanishes by parity.","lead":"This paper builds a minimal three-orbital tight-binding model of a single molecular helix and shows that the helix's handedness alone creates momentum-dependent orbital angular momentum textures, with no atomic spin-orbit coupling. The work offers a possible orbital-based explanation for chirality-induced spin selectivity and predicts measurable chirality-dependent end magnetizations.","discovery_kind":"new_application","skeptic_critique":{"model":"deepseek-v4-flash","headline":"Spin-injection superiority claim rests on unconstrained λ_z in Eq. 93; with atomic-scale λ_z, the Eq. 99 ratio is <1, so the headline overreach is not supported.","rationale":"The reader's verdict CONDITIONAL is appropriate. The strongest concern is exactly the unconstrained λ_z in the spin-injection comparison; the reader identified it and I agree. The remaining structural claims (L_r=0, odd-in-k L_φ/L_z, finite orbital Edelstein χ_L, vanishing projected longitudinal σ_L by parity) are internally consistent and analytically derived from Slater–Koster hoppings, and they do not depend on λ_z. The paper's own Appendix B only constrains λ_z in the weak-transduction limit, not its magnitude relative to α. Thus the correct action is to keep the CONDITIONAL verdict and require the authors to either derive λ_z or soften the abstract/conclusion claim. No reason to reject the paper outright, because the core OAM physics is a legitimate contribution.","tokens_in":18716,"tokens_out":4439,"duration_ms":42273,"concrete_test":"Derive λ_z from a microscopic atomic spin–orbit coupling term, H_SOC = ξ L·S, projected onto the (p_r, p_ϕ) subspace of the helix, using the appropriate atomic ξ for the light-element constituents (e.g., ξ_C ≈ 6–10 meV for carbon 2p). Insert this λ_z into Eq. 99 together with the Table I values t_rφ = 3.5 meV and Ω_z ≈ 150 meV, and evaluate the ratio for all relevant k_F. If the ratio is <1 for all k_F, the 'stronger candidate' claim fails and should be removed or heavily qualified; if no such atomic ξ yields λ_z ≫ α, the claim is not justified.","verdict_should_be":"UNCHANGED","load_bearing_attack":"The central OAM-texture results are analytically solid: the vanishing L_r follows from the phase gauge choice, the odd-in-k L_φ and L_z follow from the antisymmetric Slater–Koster hoppings, and the vanishing projected longitudinal orbital-current conductivity is a parity consequence of v^2(k) multiplying an odd texture. These stand independently.\n\nThe load-bearing weakness is the 'stronger candidate for spin injection' claim. It relies on the effective transduction H_LS=(λ_z/2ℏ)L_zσ_z introduced in Eq. 93. λ_z is never derived or numerically constrained. The comparison in Eq. 99 — δS_helix+LS/δS_SOC ~ λ_z t_rφ/(α Ω_z) — only exceeds unity if λ_z > α Ω_z/t_rφ. With Table I values (t_rφ ≈ 3.5 meV, Ω_z ≈ 0.15 eV from the ε_r−ε_φ splitting), this requires λ_z ≳ 40α. If λ_z is the atomic spin–orbit scale (a few meV for carbon 2p orbitals), the ratio is ~0.02–0.1, making the orbital route weaker, not stronger. Appendix B's weak-transduction assumption (λ_z/2 ≪ Ω_z) does not justify λ_z ≫ α; it only bounds λ_z from above. The paper neither derives λ_z from the molecular Hamiltonian nor fits it to data, so the abstract's central promotional claim is unsupported. This does not invalidate the orbital Edelstein/texture results, but it would require a new physical mechanism for λ_z to be an order of magnitude larger than the bare atomic SOC while still leaving the original SOC weak.","agreement_with_reader":"agree"},"referee_report":{"model":"deepseek-v4-flash","summary":"The paper presents a three-orbital tight-binding model of a single helix in a local (p_r, p_phi, p_z) basis, with Slater–Koster hoppings fixed by the helix geometry. The authors derive the Bloch Hamiltonian and exact eigenstates, and show that the local orbital-angular-momentum texture has an identically vanishing radial component while the azimuthal and longitudinal components are odd in momentum. They then argue that the equilibrium texture averages to zero, but that equilibrium orbital currents can survive and, at a finite helix terminus, produce chirality-dependent end magnetization. In linear response, they obtain a finite orbital Edelstein susceptibility and a vanishing projected longitudinal orbital-current conductivity on parity grounds. Finally, introducing an effective orbital-to-spin coupling proportional to an unconstrained scale lambda_z, they claim that this transduction route is stronger than conventional spin Edelstein. The central OAM texture and linear-response results are analytic and internally consistent; the spin-injection superiority claim depends on an unconstrained parameter.","tokens_in":19175,"tokens_out":9560,"duration_ms":86815,"significance":"The structural OAM results are parameter-free parity statements: the vanishing L_r follows from the phase structure of the Bloch eigenstates, the odd-in-k L_phi and L_z follow from the antisymmetric Slater–Koster hoppings, and the vanishing projected longitudinal orbital-current conductivity follows from the parity of v^2(k) times an odd texture. This is a valuable minimal model that identifies chirality as the minimal ingredient for an orbital Edelstein response and gives a transparent basis for later double-helix generalizations. The explicit Slater–Koster construction and the exact eigenstates are strengths. The input parameters are imported from the DNA literature rather than fitted to the target effect, which is appropriate for a proof-of-principle. However, the advertised spin-injection result is not on the same footing: it relies on an effective interaction with a free scale lambda_z, so the quantitative comparison with the conventional spin Edelstein mechanism is not controlled.","major_comments":[{"comment":"The abstract and Section VII state that the orbital-to-spin transduction route 'is a stronger candidate for spin injection' than the conventional spin Edelstein mechanism. This is not established. The scale lambda_z in Eq. (93) is a free parameter: the paper neither derives it from the molecular Hamiltonian nor fits it to data. According to Eq. (99), deltaS_helix+LS/deltaS_SOC ~ lambda_z t_rphi/(alpha Omega_z). With the Table I values (t_rphi ~ 3.5 meV and Omega_z set by the epsilon_r-epsilon_phi splitting, ~0.15 eV), the ratio exceeds unity only if lambda_z >~ 40 alpha. If lambda_z is the atomic C 2p spin-orbit scale (a few meV), the ratio is ~0.02-0.1 and the orbital route is weaker, not stronger. Appendix B's weak-transduction condition (lambda_z/2 << Omega_z) is an upper bound and does not justify lambda_z >> alpha. The claim should be removed or made explicitly conditional on a micr","section":"Section V, Eqs. (93) and (99)"},{"comment":"The equilibrium persistent-like current and end-magnetization argument relies on the torque T_phi in the continuity equation (69). T_phi is introduced as 'due to the ending interface or coupling to the lattice' but is never derived or estimated. In the translationally invariant infinite chain, the local L_alpha operators do not commute with the inter-site hoppings, so a bulk torque should appear in the continuity equation even without boundaries; the paper does not separate bulk from boundary contributions. Consequently, the claim that interrupting an equilibrium current at the ends produces chirality-dependent end magnetization (Fig. 6 and Eq. (70)) is not demonstrated. This is load-bearing for the abstract's equilibrium claim and should be either substantiated by a microscopic computation of the torque or presented as a qualitative scenario.","section":"Section III, Eq. (69)"},{"comment":"The vanishing longitudinal orbital-current conductivity is demonstrated only for the projected intraband contribution j_alpha,nu ~ v_nu <L_alpha>_nu. The text then asserts that finite conductivity 'will not be achieved by including the full anticommutator (due to parity)', but the full band-diagonal matrix element of (1/2){v,L} includes interband terms and is not computed. The parity argument applied to v^2<L> does not by itself rule out interband contributions. The abstract and conclusions are careful to say 'projected', but the stronger assertion in Section IV should be removed or proven; otherwise the statement exceeds what the calculation supports.","section":"Section IV, Eqs. (77)-(78)"}],"minor_comments":[{"comment":"The sentence 'for a single helical (see Fig. 1)' should read 'for a single helix'.","section":"Section II, first paragraph"},{"comment":"Typo: 'positive quirality' should be 'positive chirality'.","section":"Fig. 7 caption"},{"comment":"Typos: 'the the average textures' and 'crystaline uniaxial crystals' should be corrected. Also, the sentence about lambda_z replacing alpha is repeated from Section V and should be harmonized with the lambda_z caveat.","section":"Section VII"},{"comment":"Table I has a formatting typo in the heading ('V alue'). Reference [46] should be cited at the point where the numerical values are first introduced rather than only in the appendix.","section":"Table I and text"},{"comment":"Reference [45] contains incomplete author entries ('D. K., A. D., ...'); this should be fixed before publication.","section":"References"},{"comment":"The sentence 'We discuss possible orbital-to-spin conversion pathways in the bulk of the molecule, introducing the Spin-Orbit-Coupling, which can reconcile...' is garbled and should be rephrased.","section":"Introduction"}],"recommendation":"major_revision","confidential_remarks":"The core OAM-texture and linear-response calculations are sound and could make a good paper. The main issue is the unsupported spin-injection superiority claim, which is advertised in the abstract and conclusions but relies on the free scale lambda_z. I agree with the stress-test concern: the ratio in Eq. (99) is <1 for atomic-scale lambda_z, so the claim is not merely unproven but likely false for natural parameter choices. This is fixable by removing or strongly qualifying the claim, or by deriving lambda_z. The equilibrium torque argument is also underdeveloped. I would not reject because the central structural results stand independently and are analytically solid. The citation pattern is mostly unproblematic; the authors' own prior relevant work is cited appropriately."},"author_rebuttal":null,"desk_editor":{"model":"deepseek-v4-flash","letter":"Dear colleague,\n\nThe main thing to know: the orbital angular momentum texture results in this paper are real and worth taking seriously. The model is minimal — three p-orbitals per site on a helix — and the structural results are parameter-free parity statements: L_r vanishes identically, L_phi and L_z are odd in k, the equilibrium texture sums to zero, the orbital Edelstein susceptibility is finite, and the projected longitudinal orbital-current conductivity vanishes by parity. These follow cleanly from the even/odd structure of the Bloch Hamiltonian, and the exact eigenfunctions in Sec. II are careful. The parameters are imported from B-DNA Slater–Koster literature, not fitted to the effect, which is a point in the paper's favor. The authors are also honest about the limitations of the single-helix projection for the current conductivity.\n\nThe soft spot is the abstract's promotional claim that the orbital route is a 'stronger candidate for spin injection than the conventional spin Edelstein mechanism.' That is not supported. The transduction Hamiltonian H_LS = (λ_z/2ℏ)L_z σ_z in Eq. 93 is put in by hand. λ_z is free: not derived, not fitted, not bounded from below. The comparison ratio in Eq. 99 is λ_z t_rφ/(α Ω_z). With the table's numbers, t_rφ ≈ 3.5 meV and Ω_z ≈ 0.15 eV, so the ratio exceeds one only if λ_z ≳ 40α. If λ_z is the atomic SOC scale, a few meV, the ratio is ~0.02–0.1, and the orbital route is weaker, not stronger. Appendix B only imposes λ_z/2 ≪ Ω_z, an upper bound. So the headline overreach is real.\n\nThe end-magnetization estimate is heuristic; it relies on an unspecified boundary torque T_ϕ. That is a minor gap, clearly flagged as an estimate. The comparison with the spin Edelstein effect also uses a different geometry — a single-orbital chain against the two-orbital block — so it is not apples-to-apples.\n\nNone of this breaks the central texture results. The parity arguments stand on their own and are a genuine contribution. The paper deserves a serious referee, but the authors should be told to constrain or remove λ_z, add a same-geometry baseline for the spin Edelstein response, and soften the 'stronger candidate' language in the abstract and Sec. V. With those changes, this is a publishable contribution.\n\nMy recommendation: send to peer review, conditional on revision. The core is solid; the spin-injection claim needs to be brought in line with the evidence.\n\nBest,\n[You]","headline":"Solid OAM-texture results for the single helix; the 'stronger spin injection' claim does not survive contact with its own free parameter.","tokens_in":19666,"tokens_out":5176,"would_cite":true,"duration_ms":47591,"reading_group":"maybe","serious_thinker":"yes","would_accept_peer_review":true},"rs_alignment":null,"lean_confirmation":null,"pith_extraction":{"msc":[],"pacs":[],"model":"deepseek-v4-flash","headline":"A single helical chain develops orbital angular momentum textures and currents from chirality alone, with no atomic spin–orbit coupling required.","keywords":["orbital angular momentum","tight-binding model","chirality","helix","orbital Edelstein effect","spin selectivity","Slater-Koster hybridization","CISS"],"falsifier":"Compute or measure the ratio of spin signals δS^(helix+LS) / δS^(SOC) for a molecular realization; if the effective λ_z inferred from experiment does not exceed roughly 40α for the paper's representative parameters, the orbital transduction does not dominate. Alternatively, a transport experiment on a single helix that detects a finite longitudinal orbital current in the linear response regime would falsify the parity-based vanishing result.","tokens_in":18532,"feed_emoji":"🌀","tokens_out":3839,"duration_ms":32075,"temperature":0.7,"pith_summary":"The paper builds a minimal three-orbital tight-binding model of a single helix and claims that the helix's geometry, not atomic spin–orbit coupling, creates momentum-dependent orbital angular momentum textures on the Bloch states. Because the textures are odd in momentum, an electric field produces a finite orbital Edelstein response while the projected longitudinal orbital current vanishes in the linear regime. In equilibrium the average texture vanishes by parity, but persistent-like orbital currents can still exist, and at the ends of a finite helix they yield chirality-dependent magnetization. When spin is included, the orbital texture can be converted into spin polarization, suggesting an orbital route to spin selectivity that does not rely on strong relativistic effects.","feed_headline":"Chirality alone generates orbital angular momentum in a helix","feed_subtitle":"A minimal model shows single-helix conductors get orbital textures and spin polarization without atomic spin–orbit coupling.","key_machinery":"The load-bearing object is the Slater–Koster hopping matrix in the local cylindrical basis (p_r, p_phi, p_z) of a single helix. The screw symmetry makes certain inter-orbital hoppings antisymmetric — t_zr = −t_rz and t_rphi = −t_phi r — producing odd-in-momentum terms in the Bloch Hamiltonian (Y_k ∝ t_rz sin ka and X_k ∝ t_rphi sin ka). These terms create the orbital textures ⟨L_phi⟩ and ⟨L_z⟩ and are the only transport-active channels. The parity structure of v_ν(k)⟨L_α⟩_ν(k) then governs which responses survive: odd texture × odd velocity gives an even product, so an equilibrium current can exist; the linear Edelstein response uses an odd texture times an odd distribution shift, while the","core_discovery":"The central claim is that in a three-orbital (p_r, p_phi, p_z) tight-binding model of a single DNA-like helix, Slater–Koster inter-orbital hoppings enforced by screw symmetry generate odd-in-momentum hybridization in the (p_z, p_r) and (p_r, p_phi) sectors. These odd channels produce azimuthal and longitudinal orbital-angular-momentum textures that are odd under k → −k, while the radial texture vanishes identically. Consequently, the equilibrium average texture vanishes by parity, but an applied longitudinal field produces a finite orbital Edelstein susceptibility χ_L. The projected longitudinal orbital-current conductivity vanishes by parity in the linear regime. When spin is included, the","pith_inferences":["The claimed superiority of the orbital route over the conventional spin Edelstein mechanism rests on an unverified coupling scale λ_z; for the paper's Table I parameters, the enhancement ratio exceeds unity only if λ_z ≳ 40 times the bare spin–orbit scale, so a quantitative comparison of λ_z with α is needed before the superiority claim can be accepted.","The parity argument that eliminates the linear longitudinal orbital current depends on the symmetric band dispersion E_ν(k) = E_ν(−k); if a single helix is driven beyond linear response or placed in an asymmetric environment, a finite orbital current could reappear, which could be tested by computing second-order response coefficients.","The predicted chirality-dependent end magnetization could be probed experimentally with local magnetic imaging on finite helical molecules or chiral crystals, comparing opposite enantiomers: the sign of the magnetization should reverse with handedness, and the largest surviving component is expected along the helix axis.","The vanishing radial orbital texture is a special consequence of the single-helix gauge structure; bringing two strands together (as in a double helix) will generically produce a nonzero radial texture with an even-in-momentum component, which would manifest as a finite linear orbital conductivity — a concrete prediction that distinguishes this model from simpler one-channel descriptions."],"forward_implications":["A single helix under bias develops a chirality-dependent orbital angular momentum accumulation (orbital Edelstein effect), observable as an orbital magnetization even with zero atomic spin–orbit coupling.","Finite helices should exhibit chirality-dependent end magnetization in equilibrium due to the interruption of persistent-like orbital currents at the boundaries.","The projected longitudinal orbital-current conductivity vanishes in the linear regime for a single helix, so the leading response is an induced orbital texture, not an orbital current; a double-helix geometry is the suggested route to a finite orbital conductivity.","The orbital texture, converted through a local spin–orbit term, can produce spin polarization whose magnitude is set by orbital overlap scales (meV) rather than the bare relativistic spin–orbit scale, providing a new orbital pathway to chirality-induced spin selectivity."],"fun_headline_variants":["Helix chirality yields orbital textures without spin-orbit coupling","Chirality drives orbital angular momentum in single helix","Helix's chirality alone creates orbital momentum response","Orbital Edelstein effect from helix chirality no spin-orbit","Odd-momentum orbital textures from helix screw symmetry"],"cache_read_input_tokens":2304,"weakest_assumption_plain":"The claim that orbital-to-spin transduction outperforms the conventional spin Edelstein mechanism relies on an introduced coupling strength λ_z that the paper neither derives nor fits; if λ_z is comparable to the bare spin–orbit scale α, the orbital route is weaker, not stronger.","fun_headline_variants_meta":{"raw":{"variants":["Helix chirality yields orbital textures without spin-orbit coupling","Chirality drives orbital angular momentum in single helix","Helix's chirality alone creates orbital momentum response","Orbital Edelstein effect from helix chirality no spin-orbit","Odd-momentum orbital textures from helix screw symmetry"]},"model":"deepseek-v4-flash","effort":"low","cost_usd":0.000611,"raw_usage":{"total_tokens":2712,"prompt_tokens":808,"completion_tokens":1904,"prompt_tokens_details":{"cached_tokens":256},"prompt_cache_hit_tokens":256,"prompt_cache_miss_tokens":552,"completion_tokens_details":{"reasoning_tokens":1835}},"tokens_in":552,"tokens_out":1904,"duration_ms":11877,"temperature":1.0,"reasoning_tokens":1835,"cache_read_input_tokens":256,"cache_creation_input_tokens":0},"cache_creation_input_tokens":0},"created_at":"2026-08-02T13:53:17.212238+00:00","model_set":{"reader":"deepseek-v4-flash"},"falsifier":"Compute or measure the ratio of spin signals δS^(helix+LS) / δS^(SOC) for a molecular realization; if the effective λ_z inferred from experiment does not exceed roughly 40α for the paper's representative parameters, the orbital transduction does not dominate. Alternatively, a transport experiment on a single helix that detects a finite longitudinal orbital current in the linear response regime would falsify the parity-based vanishing result.","supporting_citations":[],"review_version":2}