{"id":"21e8a736-3039-4b62-a144-54866f378c20","arxiv_id":"2606.10291","paper_version":1,"verdict":"UNVERDICTED","confidence":"LOW","novelty_score":6.0,"correctness_risk":"unknown","formal_verification":"none","parameter_count":0,"one_line_summary":"Uniform loss activates non-Hermitian skin effects that reshape edge-band topology into point-gap windings, converting nonchiral bidirectional interface states into unidirectional-like propagation in photonic crystals.","lead":"The paper finds that uniform loss in photonic crystals can activate non-Hermitian skin effects to turn bidirectional edge states into unidirectional-like circulation. A smart generalist might read it for a simpler route to one-way light control without needing patterned loss or nonreciprocity.","discovery_kind":"new_application","skeptic_critique":{"model":"grok-4.3","headline":"Uniform on-site loss typically shifts eigenvalues without inducing NHSE or point-gap windings unless polarization difference creates effective asymmetry at interface","rationale":"The reader's weakest assumption directly identifies the same geometry-dependent activation step. Because the provided information does not contain the explicit derivation or numerical confirmation that the polarization difference supplies the required asymmetry, the UNVERDICTED status is appropriate and no adjustment is warranted.","tokens_in":1718,"tokens_out":360,"duration_ms":26657,"concrete_test":"Construct the tight-binding or finite-element model of the core-cladding PhC with uniform -iγ added identically to both domains; compute the complex edge-band spectrum and right eigenvectors along the interface for two cases (polarizations equal vs. distinct). If point-gap winding appears and edge-mode localization length drops below system size only in the distinct-polarization case, the mechanism holds; otherwise the claim weakens.","verdict_should_be":"UNCHANGED","load_bearing_attack":"The central claim requires that uniform loss in core-cladding domains (identical Chern numbers, distinct bulk polarizations) activates NHSEs that open point gaps with nonzero winding on the edge bands. This is the least secure step: adding a uniform imaginary on-site term -iγ to a TRS-broken photonic Hamiltonian shifts the entire spectrum rigidly while leaving right eigenvectors unchanged, so no skin localization or spectral topology change occurs. The distinct bulk polarizations must therefore supply an additional effective non-reciprocity at the domain wall; if they only modulate local field intensity without breaking reciprocity in the effective 1D edge Hamiltonian, the claimed point-gap winding and unidirectional circulation do not follow. No independent check (e.g., explicit winding calculation or eigenvector localization length) is supplied in the abstract-level description.","agreement_with_reader":"agree"},"referee_report":{"model":"grok-4.3","summary":"The manuscript claims that uniform loss, applied in a core-cladding photonic-crystal geometry where the two domains share identical Chern numbers but possess distinct bulk polarizations, activates non-Hermitian skin effects that reshape the spectral topology of the edge bands. This produces point-gap windings that convert intrinsically bidirectional interface states into unidirectional-like circulation around the entire domain wall. The claim is supported by theoretical analysis of the non-Hermitian Hamiltonian and by near-field experimental measurements that show excellent agreement with the predicted one-way propagation.","tokens_in":1863,"tokens_out":469,"duration_ms":17923,"significance":"If the central mechanism is correctly demonstrated, the result supplies a structurally simple route to unidirectional-like edge transport that does not require spatially patterned loss or explicit nonreciprocity. The experimental confirmation and the use of domains with matched Chern numbers but mismatched polarizations are positive features that could make the approach broadly applicable in photonic-crystal platforms.","major_comments":[{"comment":"The load-bearing step is the assertion that uniform loss (-iγ) plus a polarization mismatch at the domain wall is sufficient to generate point-gap windings and NHSE localization on the edge bands. A uniform imaginary on-site term applied to a time-reversal-broken but otherwise reciprocal base Hamiltonian shifts the entire spectrum rigidly while leaving right eigenvectors unchanged; therefore the manuscript must explicitly derive or numerically compute the effective 1D edge Hamiltonian, evaluate its point-gap winding number, and demonstrate eigenvector localization lengths that differ from the Hermitian case. No such calculation is referenced in the abstract-level description, and the provided stress-test concern remains unresolved without it.","section":"Theory / effective edge model (likely §III or Eq. set defining the non-Hermitian edge dispersion)"}],"minor_comments":[{"comment":"Figure captions should explicitly state the value of the uniform loss parameter γ used in both simulation and experiment, together with the frequency range over which the unidirectional circulation is observed.","section":null},{"comment":"The manuscript should add a brief comparison table or plot showing the edge-state dispersion with and without the uniform loss term to make the spectral-topology change visually quantitative.","section":null}],"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. The major comment raises a valid point regarding the need for an explicit effective edge model, which we address below by committing to a targeted revision.","responses":[{"response":"We agree that the effective 1D edge Hamiltonian derivation is central and must be shown explicitly to substantiate how uniform loss combined with polarization mismatch generates point-gap windings and NHSE on the edge bands. The manuscript contains theoretical analysis of the non-Hermitian Hamiltonian, but we acknowledge that the step-by-step reduction to the edge model and the associated winding-number and localization calculations are not sufficiently highlighted. In the revised manuscript we will add a dedicated derivation of the effective non-Hermitian 1D edge Hamiltonian that incorporates the polarization mismatch at the domain wall; this mismatch produces an effective non-reciprocal interface term under uniform loss, yielding a point gap with nonzero winding. We will also report the numerically evaluated winding number and the eigenvector localization lengths, which are shortened relative to the Hermitian case. These additions will directly resolve the stress-test concern.","revision_made":"yes","referee_comment":"[Theory / effective edge model (likely §III or Eq. set defining the non-Hermitian edge dispersion)] The load-bearing step is the assertion that uniform loss (-iγ) plus a polarization mismatch at the domain wall is sufficient to generate point-gap windings and NHSE localization on the edge bands. A uniform imaginary on-site term applied to a time-reversal-broken but otherwise reciprocal base Hamiltonian shifts the entire spectrum rigidly while leaving right eigenvectors unchanged; therefore the manuscript must explicitly derive or numerically compute the effective 1D edge Hamiltonian, evaluate its point-gap winding number, and demonstrate eigenvector localization lengths that differ from the Hermitian case. No such calculation is referenced in the abstract-level description, and the provided stress-test concern remains unresolved without it."}],"tokens_in":1306,"tokens_out":405,"duration_ms":30014,"standing_objections":[]},"desk_editor":{"model":"grok-4.3","letter":"The main result is that uniform loss in a core-cladding geometry with identical Chern numbers but distinct bulk polarizations turns bidirectional nonchiral edge states into unidirectional-like circulation through NHSE and point-gap windings.\n\nWhat is new is the claim that uniform loss alone, without patterning or explicit nonreciprocity, suffices in this setup and was previously overlooked.\n\nThe paper does well by combining the theoretical description of how loss reshapes edge-band topology with near-field measurements that show the expected one-way propagation around the domain wall and match the model.\n\nThe soft spot is exactly the step the stress-test flags: uniform on-site loss shifts the spectrum rigidly and leaves right eigenvectors unchanged, so it does not by itself produce skin localization or point-gap winding. The distinct polarizations must therefore supply an additional effective non-reciprocity at the interface. The abstract leaves this implicit and supplies no explicit winding numbers or localization-length calculations, so it is not possible to judge whether the polarization difference actually does the required work or whether other interface effects are at play.\n\nThis is for researchers in non-Hermitian topological photonics who want simpler routes to unidirectional transport. It has enough theory-plus-experiment content to deserve a serious referee, even if the central mechanism will need clearer derivation in revision.","headline":"Uniform loss activates NHSE-driven unidirectional edge transport in core-cladding PhCs via polarization differences, but the effective asymmetry step is the least secure part.","tokens_in":2360,"tokens_out":337,"would_cite":false,"duration_ms":16541,"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":"Uniform loss in photonic crystals with matched Chern numbers but different polarizations induces unidirectional-like edge transport through non-Hermitian skin effects.","keywords":["non-Hermitian skin effects","photonic crystals","unidirectional edge transport","point gap windings","Chern numbers","uniform loss","bulk polarizations"],"falsifier":"A direct observation of persistent bidirectional propagation or absence of point-gap windings under uniform loss in the described core-cladding photonic crystal setup would falsify the central claim.","tokens_in":2615,"feed_emoji":"🔬","tokens_out":539,"duration_ms":20384,"temperature":0.7,"pith_summary":"The paper establishes that uniform loss, rather than requiring engineered nonreciprocity or patterned loss, can enforce unidirectional-like edge transport in photonic crystals. It does so in a core-cladding geometry where domains have identical Chern numbers but distinct bulk polarizations. Uniform loss activates non-Hermitian skin effects that reshape edge band topology into point-gap windings, which dictate one-way propagation. This converts intrinsically bidirectional interface states into circulating modes around the domain wall. Near-field experiments confirm the effect, matching theoretical predictions.","feed_headline":"Uniform loss creates one-way edge transport in photonic crystals","feed_subtitle":"Core-cladding structures with same Chern numbers but different polarizations use uniform loss to induce skin effects and point-gap windings","key_machinery":"Uniform loss activating non-Hermitian skin effects in core-cladding geometries to produce point-gap windings that enforce one-way edge transport.","core_discovery":"In a core-cladding photonic crystal geometry where domains share identical Chern numbers but possess distinct bulk polarizations, uniform loss activates non-Hermitian skin effects that reshape the spectral topology of edge bands into point gap windings. These windings dictate unidirectional-like propagation, converting bidirectional interface states into one-way circulation around the domain wall even with nonchiral edge states.","pith_inferences":["This approach could simplify fabrication of unidirectional photonic devices by eliminating the need for loss patterning.","The effect may generalize to other wave systems such as acoustic or mechanical metamaterials.","Adjusting loss magnitude offers a tunable control over the unidirectionality strength."],"forward_implications":["Uniform loss suffices for unidirectional-like transport without engineered nonreciprocity or patterned loss.","Bidirectional interface states convert to unidirectional-like circulation around the domain wall.","Point-gap windings in edge band spectra dictate the propagation direction.","The mechanism applies to nonchiral edge states in structures with matched Chern numbers."],"fun_headline_variants":["Uniform loss induces skin effects yielding unidirectional-like edge transport","Skin effects from uniform loss enable one-way circulation in photonic crystals","Uniform loss creates point gap windings dictating unidirectional edge transport","Loss driven skin effects reshape edge bands into unidirectional-like propagation"],"cache_read_input_tokens":2112,"weakest_assumption_plain":"The core-cladding geometry in which domains share identical Chern numbers but possess distinct bulk polarizations will allow uniform loss to activate NHSEs that reshape the spectral topology of edge bands into point-gap windings without additional confounding effects from the specific material or fabrication details.","fun_headline_variants_meta":{"raw":{"variants":["Uniform loss induces skin effects yielding unidirectional-like edge transport","Skin effects from uniform loss enable one-way circulation in photonic crystals","Uniform loss creates point gap windings dictating unidirectional edge transport","Loss driven skin effects reshape edge bands into unidirectional-like propagation"]},"model":"grok-4.3","cost_usd":0.00804,"raw_usage":{"total_tokens":3540,"prompt_tokens":594,"num_sources_used":0,"completion_tokens":58,"cost_in_usd_ticks":80403000,"prompt_tokens_details":{"text_tokens":594,"audio_tokens":0,"image_tokens":0,"cached_tokens":64},"completion_tokens_details":{"audio_tokens":0,"reasoning_tokens":2888,"accepted_prediction_tokens":0,"rejected_prediction_tokens":0}},"tokens_in":594,"tokens_out":58,"duration_ms":17545,"temperature":1.0,"reasoning_tokens":2888,"cache_read_input_tokens":64,"cache_creation_input_tokens":0},"cache_creation_input_tokens":0},"created_at":"2026-06-27T12:37:18.797240+00:00","model_set":{"reader":"grok-4.3"},"falsifier":"A direct observation of persistent bidirectional propagation or absence of point-gap windings under uniform loss in the described core-cladding photonic crystal setup would falsify the central claim.","supporting_citations":[],"review_version":1}