{"id":"cacc81fd-3e0c-499e-88e3-63e31b1259d1","arxiv_id":"2501.13140","paper_version":1,"verdict":"CONDITIONAL","confidence":"MODERATE","novelty_score":6.0,"correctness_risk":"medium","formal_verification":"none","parameter_count":5,"one_line_summary":"A single anti-resonance mode can couple coherently or dissipatively to different magnon modes depending on the strength of the microwave magnetic field at the magnon position, enabling magnetic-field-selective microwave transmission.","lead":"The authors report experiments in which magnon modes in a YIG wafer couple to the same anti-resonance of a microwave cavity, alternately forming dissipative or coherent couplings depending on the magnon's microwave field profile at the wafer position. The result suggests a design rule for magnetic-field-selective microwave transmission and could lead to a magnetic-tuning switch, if the empirical correlation holds beyond the two cavities tested.","discovery_kind":"new_application","skeptic_critique":{"model":"deepseek-v4-flash","headline":"The claimed field-strength law is underdetermined because the simulated magnon-mode field strength is never given a scale-invariant quantitative definition, and the fitted J/Γ labels have no uncertainties.","rationale":"I read the paper in good faith. The experiment is well-posed: two cavities, multiple magnon modes, and a plausible mechanism for anti-resonance-mediated dissipative coupling. The two-cavity check is a genuine strength. However, the paper's own central conclusion is stated as a quantitative design rule ('as weak as possible'), and the support for that rule is a visual comparison of color maps plus a table of fitted couplings without uncertainties. The most load-bearing assumption is therefore not the phase criterion per se, which is ambiguous even within the paper (c2 and c3 share the same phase sign but are assigned different coupling types), but the existence of a meaningful, comparable field-strength quantity across modes. In linear eigenmode simulations, absolute mode amplitudes are not physically meaningful unless the normalization is tied to a common drive; the Min/Max bars in the figures suggest per-panel normalization. Without reporting a normalization-invariant metric such as an overlap integral or a common-excitation rms field, the claimed weak/strong dichotomy is unfalsifiable. A further, related weakness is the absence of uncertainties on J and Γ; some Table I entries are close to the dissipative/coherent boundary, so the correlation could partly be a fit artifact. These concerns do not prove the claim false; they do mean the paper should not move past CONDITIONAL without the quantitative metric and error analysis. I agree with the reader that missing error bars and a quantitative field-strength metric matter, and I add the normalization/scale-arbitrariness point as the sharpest formulation. No change in verdict: still CONDITIONAL.","tokens_in":9933,"tokens_out":13920,"duration_ms":153748,"concrete_test":"Use the existing COMSOL models to compute, for each magnon mode that crosses the anti-resonance frequency in both cavities, two scale-invariant quantities under one common simulation normalization: (i) the normalized overlap integral O = |∫ h_m*·h_c dV| / (sqrt(∫|h_m|²dV) sqrt(∫|h_c|²dV)) over the YIG volume, where h_c is the anti-resonance cavity field and h_m is the magnon-mode field, and (ii) the rms |h_m| inside the YIG with the same port excitation for every mode. Then reclassify each mode by fitting the S21 maps with bootstrap resampling to obtain 95% confidence intervals for J and Γ. If dissipative modes (Γ>J) do not systematically occupy the low-O or low-rms region, or if any label flips within 2σ, the central correlation is not established.","verdict_should_be":"UNCHANGED","load_bearing_attack":"The central design rule—weak microwave-field distribution of the magnon mode at the anti-resonance frequency implies dissipative coupling—is load-bearing because the whole paper is built on reading this correlation off Figs. 3 and 5. Three things make the correlation insecure. First, the strength of the magnon-mode field is never defined quantitatively. The color maps in Figs. 3(c) and 5(c) are labeled Min/Max, which normally means each panel is normalized to its own maximum; for linear eigenmode simulations the absolute amplitude is also arbitrary unless a common excitation normalization is specified. Notably weak versus notably strong is therefore not a well-defined scalar across modes. Second, the coherent/dissipative labels come from fitting Eq. (4), but Table I gives no uncertainties; several entries are close to the boundary (e.g., stadium navy J/2π=7 MHz, Γ/2π=9.8 MHz) and could flip under fit noise or an alternative θ value. Third, the phase-change criterion stated after Fig. 2(c) cannot by itself anchor the labels: c2 and c3 both have positive phase changes, yet they are assigned coherent and dissipative couplings respectively, so the classification rests on the fits, not on the bare phase sign. If the field-strength metric is not meaningful or if even one borderline label flips, the claimed law loses its support.","agreement_with_reader":"partial"},"referee_report":{"model":"deepseek-v4-flash","summary":"The manuscript reports cavity-magnonics experiments in a rectangular (integrable) cavity and a quadrant-stadium (chaotic) cavity, in which a single anti-resonance mode at 11.367 GHz and 13.05 GHz respectively interacts with the ferromagnetic resonance (FMR) mode and several forward volume magnetostatic spin-wave (FVMSW) modes of a YIG wafer. By fitting transmission dispersions branch by branch with the two-mode non-Hermitian Hamiltonian in Eq. (4), the authors classify each magnon branch as either coherently or dissipatively coupled to the anti-resonance. They observe that modes whose simulated microwave magnetic field at the anti-resonance frequency is weak tend to be dissipatively coupled, while modes with stronger field distributions tend to be coherently coupled. On this basis they propose a field-distribution design rule and demonstrate a field-controlled transmission feature at the anti-resonance frequency, which they propose as a magnetic-tuning switch.","tokens_in":10319,"tokens_out":7924,"duration_ms":80075,"significance":"If established, the claimed rule would be a practical design principle for engineering coherent versus dissipative magnon-photon coupling without changing material parameters. The paper is valuable in showing both coupling types with the same anti-resonance mode and in testing the idea in two qualitatively different cavities, with raw transmission maps and explicit J/Γ values in Table I that are useful data. However, the quantitative support for the central correlation is currently insufficient: the field-strength comparison is qualitative and scale-dependent, the Eq. (4) fits carry no uncertainties, some labels are close to the coherent/dissipative boundary, and the correlation is demonstrated on the same data from which the labels were extracted rather than through an independent prediction. These issues must be addressed before the central claim is established.","major_comments":[{"comment":"The paper's load-bearing claim is that the magnon-mode field strength at the anti-resonance frequency determines the coupling type. This is supported only by qualitative inspection of color maps labeled 'Min'/'Max'. Because each panel appears normalized to its own maximum and the eigenmode simulations have arbitrary global amplitude, 'weak' versus 'strong' is not a scale-invariant quantity, and no threshold is defined. In addition, the correlation is demonstrated on the same data used to extract the labels, so it is not yet an independent prediction. Please define a quantitative, normalized field-strength measure (e.g., the overlap integral of the magnon-mode microwave field with the anti-resonance cavity field over the wafer volume) and report it for all seven branches in both cavities.","section":"Results and discussion, Figs. 3(b)-(c) and 5(b)-(c)"},{"comment":"Table I lists J and Γ for seven branches per cavity but gives no uncertainties or goodness-of-fit metrics. The reader cannot judge whether the coherent/dissipative assignments are robust; for example, the quadrant-stadium navy branch has J/2π=7 MHz and Γ/2π=9.8 MHz, within about 40% of the coherent-dominated boundary, and fit noise or an alternative θ value could flip the label. Since these labels are the dependent variable of the paper, please report fit uncertainties (e.g., from least-squares covariance or bootstrap), the θ values used for each branch, and at least one representative overlay of the fitted eigenvalues on the measured dispersion.","section":"Table I and fits to Eq. (4)"},{"comment":"The phase-change criterion presented after Fig. 2(c) does not by itself establish the coherent/dissipative labels. The text states that both c2 and c3 have 'positive' phase changes, yet c2 is assigned coherent coupling and c3 is assigned dissipative coupling; hence the phase sign cannot be the operative discriminator between the two coupling types for the magnon modes. Please clarify that the phase sign only identifies the anti-resonance mode c3 while the coherent/dissipative classification comes from the Eq. (4) fits, or provide an independent phase-based test.","section":"Paragraph after Fig. 2(c)"},{"comment":"The fits to Eq. (4) are performed independently for each magnon branch even though all branches are simultaneously present in the same measured S21 map and share the same anti-resonance background. The two-mode model therefore neglects inter-magnon-mode couplings and interfering background contributions, which can bias the extracted J and Γ values. Because those values are the evidence for the central field-strength law, please show that the independent-branch approximation reproduces the full measured lineshape (e.g., residuals or a multi-mode fit), or justify why the omitted modes cannot alter the assignments.","section":"Results and discussion, fits to Eq. (4)"}],"minor_comments":[{"comment":"The word 'sindicating' should be 'indicating'.","section":"Paragraph after Eq. (4)"},{"comment":"The caption says 'The amplitude and phase of of the rectangular cavity' but the panel is for the quadrant-stadium cavity; please correct the cavity name and remove the doubled 'of'.","section":"Fig. 4(b) caption"},{"comment":"'The associated origin and purple dots indicate coherent coupling' appears to refer to the orange and violet dots in Fig. 5(a); please correct the color names.","section":"Text after Fig. 5(c)"},{"comment":"The manuscript does not explain how the phase θ in Eq. (3) is chosen for each fitted branch; since the couplings depend on θ, this information is needed to reproduce the fits.","section":"Eq. (3) and fitted values"},{"comment":"The statement that dissipative coupling 'could only appear at the frequency of the anti-resonance mode' is stronger than the evidence, which covers one anti-resonance per cavity at a single YIG wafer position; please condition the claim on the tested configurations.","section":"Conclusion"}],"recommendation":"major_revision","confidential_remarks":"For the editor: the manuscript is potentially interesting, but the central correlation is currently under-supported. The revision should focus on quantitative field metrics, fit uncertainties, and an independent check of the design rule rather than on new physics. Please also ask the authors to sharpen the relation to Refs. [35] and [51]; at present the novelty is the field-distribution rule, so the strength of the evidence for that rule will determine whether the paper meets the journal's bar."},"author_rebuttal":null,"desk_editor":{"model":"deepseek-v4-flash","letter":"The thing to know: this paper shows the same anti-resonance mode coupling dissipatively to the FMR mode and coherently to FVMSW modes, and the pattern correlates with whether the magnon mode's microwave magnetic field is weak or strong at the YIG location. They reproduce the alternation in a second, chaotic cavity, which is the strongest part of the evidence. That is a real empirical result, not a repackaging.\n\nWhat's genuinely new: previous work had anti-resonance dissipative coupling (Rao, Bourcin et al.) and multimode coherent coupling (Zhang et al.) separately; here the two appear together against one anti-resonance, and the field-strength correlation is a plausible design rule. The transmission maps and Table 1 fits are consistent, and the switch-like selective transmission demo in Fig. 6 is a nice practical consequence.\n\nThe soft spots are real but not fatal. First, the central rule is qualitative: the simulated field maps are normalized per panel, so \"weak\" and \"strong\" have no common scale across modes. A quantitative metric, e.g., overlap of the magnon mode field with the anti-resonance cavity field at the wafer location, would make the claim testable. Second, Table I gives no uncertainties; a few entries (stadium navy J/2π=7, Γ/2π=9.8 MHz, for instance) are close enough that different fit choices could flip the label. Third, the phase-change criterion after Fig. 2(c) cannot alone anchor the labels: c2 and c3 both have positive phase changes yet are assigned coherent and dissipative. The classifications rest on the Eq. (4) fits, which is fine, but the text makes it sound like the phase sign is decisive. These are presentation and rigor issues, not evidence that the observation is wrong.\n\nFor whom: experimentalists in cavity magnonics, especially people designing hybrid magnon-photon devices. The work is a solid experimental contribution that deserves serious referee time, but the referees should ask for error bars, a defined field-strength metric, and the supplementary parameters before acceptance.","headline":"A genuinely new empirical correlation in cavity magnonics—dissipative versus coherent anti-resonance coupling tracks whether the magnon's rf field is weak or strong at the sample—shown in two cavities, but the 'law' stays qualitative.","tokens_in":10801,"tokens_out":1577,"would_cite":true,"duration_ms":17908,"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":"This paper claims that a single cavity anti-resonance mode can couple to different magnon modes either dissipatively or coherently, with the magnon mode's microwave magnetic field strength at the anti-resonance frequency deciding which…","keywords":["cavity magnonics","dissipative coupling","coherent coupling","anti-resonance","magnon modes","yttrium iron garnet","forward volume magnetostatic spin waves","magnetic-tuning switch"],"falsifier":"Place the YIG wafer at a cavity position where finite-element simulation predicts a strong microwave magnetic field for the FMR mode at the anti-resonance frequency and measure the coupling; the paper's rule predicts coherent coupling, so observing dissipative coupling in that configuration would falsify the claim.","tokens_in":9764,"feed_emoji":"🧲","tokens_out":11997,"duration_ms":112813,"temperature":0.7,"pith_summary":"This paper tries to establish a simple design rule for hybrid magnon-photon systems: the same anti-resonance mode of a microwave cavity can couple to different magnon modes either dissipatively or coherently, and the deciding factor is the microwave magnetic field of the magnon mode at the anti-resonance frequency. Weak field distribution favors dissipative coupling; strong field distribution favors coherent coupling. The authors realize both couplings simultaneously in a single cavity containing a YIG wafer, and show that sweeping an applied magnetic field makes the system alternate between the two regimes over a wide field range. This matters because it turns a single device into a continuously field-tunable microwave switch and gives experimenters a spatial criterion for choosing where to place a magnetic sample. The rule is demonstrated in two cavity geometries, a rectangular cavity and a chaotic quadrant-stadium cavity.","feed_headline":"Weak magnon fields give dissipative coupling, strong fields coherent","feed_subtitle":"The same anti-resonance switches coupling type with applied field, enabling a magnetic microwave switch.","key_machinery":"The load-bearing object is the anti-resonance mode $\\hat{c}_3$, a transmission dip generated jointly by two cavity modes $\\hat{c}_1,\\hat{c}_2$ and two input/output connectors, at 11.367 GHz in the rectangular cavity and 13.05 GHz in the quadrant-stadium cavity. The fits are made with a non-Hermitian Hamiltonian whose magnon-photon interaction is a complex coupling $J - i\\Gamma e^{i\\theta}$, where $J$ is the coherent coupling strength, $\\Gamma$ the dissipative coupling strength, and $\\theta$ the phase difference of the microwave drive at the two ports; its two eigenvalues give the level repulsion or level attraction used to extract the numbers in Table I. The second piece of machinery is finite-element simulation of the microwave magnetic field of each magnon mode at the anti-resonance frequency, which supplies the weak-field/strong-field distinction that the paper correlates with dissipative/coherent character. The magnon modes themselves are identified using the Kittel equation for FMR and the Damon-Eshbach dispersion for FVMSW, with wave vectors from Bessel-function roots.","core_discovery":"The paper's central claim is that, in a quasi-closed microwave cavity loaded with a yttrium iron garnet (YIG) wafer, the same anti-resonance mode can couple to different magnon modes in opposite ways depending on the microwave magnetic field of the magnon mode at the anti-resonance frequency. At the anti-resonance at 11.367 GHz in the rectangular cavity, the ferromagnetic resonance (FMR) mode has a weak field at the wafer and couples dissipatively, with fitted strengths $\\Gamma/2\\pi = 70$ MHz and $J/2\\pi = 1$ MHz, while the forward volume magnetostatic spin wave (FVMSW) modes have strong fields and couple coherently, the lowest-order mode with $\\Gamma/2\\pi = 5$ MHz and $J/2\\pi = 40$ MHz. The same pattern is reproduced in a quadrant-stadium (chaotic) cavity at the anti-resonance at 13.05 GHz, where the coupling type alternates between dissipative and coherent as successive magnon modes cross the anti-resonance, and finite-element simulations of the magnon field distributions match the assignment: weak field means dissipative, strong field means coherent. The authors conclude that dissipative coupling appears only at the anti-resonance frequency and only when the magnon mode's microwave field at that frequency is as weak as possible, and they use the alternating couplings to make microwave transmission at the anti-resonance frequency switchable by applied magnetic field.","pith_inferences":["The paper fits $\\Gamma$ and $J$ separately for each mode; a parameter-free extension would be to compute the overlap integral between the magnon mode's microwave field and the cavity field at the anti-resonance and predict the ratio $\\Gamma/J$ from it.","The geometric rule suggests a design path the paper does not explore: patterning a magnetic film so that selected magnon modes have nodal, weak-field profiles at the anti-resonance frequency would let one engineer dissipative coupling on demand.","The same weak-field/strong-field correlation may hold in other quasi-closed cavity geometries and other magnetic materials, which could turn the demonstrated rule into a general platform rule rather than a YIG-specific effect.","If the phase-change criterion and the field-strength rule are connected, then a direct measurement of the complex transmission phase across each avoided crossing should determine the coupling type without separate fits; that would be a sharp test of the mechanism."],"forward_implications":["A single anti-resonance mode can replace the usual either-or choice in cavity magnonics: different magnon modes in the same sample give dissipative and coherent coupling at the same cavity frequency.","The weak-field/strong-field rule becomes a geometric design criterion for placing magnetic samples in quasi-closed cavities.","Because the applied magnetic field moves successive magnon modes through the anti-resonance, the system alternates between the two coupling regimes and acts as a continuously tunable microwave switch.","In the chaotic cavity, the competition between coherent and dissipative coupling suppresses the lower polariton branch, which sharpens the transmission windows observed at the anti-resonance.","Systems that need both coupling types together, for example for nonreciprocal or long-distance magnon-photon control, can now be built with one cavity instead of separate setups."],"supporting_citations":[{"why":"This work supplies the anti-resonance picture and the phase-based criterion used to label dissipative coupling.","marker":"[51]"},{"why":"This prior work demonstrated dissipative coupling between an FMR mode and an anti-resonance in a quasi-closed system, providing the baseline this paper extends.","marker":"[35]"},{"why":"The supplementary material provides the cavity dimensions, connector parameters, dissipation rates, and eigenmode simulation details used in the experiment.","marker":"[52]"},{"why":"This earlier paper by the same group realized coherent multimode couplings among cavity, FMR, and FVMSW modes, which this work reuses and extends to the same anti-resonance.","marker":"[44]"},{"why":"This source supplies the non-Hermitian Hamiltonian with complex coupling that the authors use to extract the coherent and dissipative coupling strengths.","marker":"[60]"},{"why":"This reference gives the FVMSW dispersion formula used to identify the higher-order magnon modes.","marker":"[57]"},{"why":"The Kittel equation from this reference fixes the FMR frequency used to label the ferromagnetic resonance line.","marker":"[55]"},{"why":"This reference provides the Bessel-function roots used to compute the FVMSW wave vectors.","marker":"[59]"}],"fun_headline_variants":["Anti-resonance flips magnon coupling from dissipative to coherent","Weak magnon field dissipates, strong field coheres at anti-resonance","Field strength selects coupling type at a single anti-resonance","Same anti-resonance toggles magnon coupling with magnetic field","Magnon field shapes coupling: weak = loss, strong = coherence"],"cache_read_input_tokens":3200,"weakest_assumption_plain":"The central claim depends on the criterion, taken from earlier work on cavity anti-resonances, that the sign of the cavity mode's phase change at the anti-resonance tells whether a coupling is dissipative or coherent; if that phase-based labeling is wrong for this multimode geometry, the dissipative/coherent assignments and the field-strength correlation would have to be redone.","fun_headline_variants_meta":{"raw":{"variants":["Anti-resonance flips magnon coupling from dissipative to coherent","Weak magnon field dissipates, strong field coheres at anti-resonance","Field strength selects coupling type at a single anti-resonance","Same anti-resonance toggles magnon coupling with magnetic field","Magnon field shapes coupling: weak = loss, strong = coherence"]},"model":"deepseek-v4-flash","effort":"low","cost_usd":0.000163,"raw_usage":{"total_tokens":1253,"prompt_tokens":962,"completion_tokens":291,"prompt_tokens_details":{"cached_tokens":384},"prompt_cache_hit_tokens":384,"prompt_cache_miss_tokens":578,"completion_tokens_details":{"reasoning_tokens":196}},"tokens_in":578,"tokens_out":291,"duration_ms":3660,"temperature":1.0,"reasoning_tokens":196,"cache_read_input_tokens":384,"cache_creation_input_tokens":0},"cache_creation_input_tokens":0},"created_at":"2026-08-10T16:40:57.455711+00:00","model_set":{"reader":"deepseek-v4-flash"},"falsifier":"Place the YIG wafer at a cavity position where finite-element simulation predicts a strong microwave magnetic field for the FMR mode at the anti-resonance frequency and measure the coupling; the paper's rule predicts coherent coupling, so observing dissipative coupling in that configuration would falsify the claim.","supporting_citations":[{"cited_title":"Lecocq, L","cited_arxiv_id":null,"evidence_quote":"This work supplies the anti-resonance picture and the phase-based criterion used to label dissipative coupling."},{"cited_title":null,"cited_arxiv_id":null,"evidence_quote":"This prior work demonstrated dissipative coupling between an FMR mode and an anti-resonance in a quasi-closed system, providing the baseline this paper extends."},{"cited_title":"Bourcin, A","cited_arxiv_id":null,"evidence_quote":"The supplementary material provides the cavity dimensions, connector parameters, dissipation rates, and eigenmode simulation details used in the experiment."},{"cited_title":"Yang, Y.-P","cited_arxiv_id":null,"evidence_quote":"This earlier paper by the same group realized coherent multimode couplings among cavity, FMR, and FVMSW modes, which this work reuses and extends to the same anti-resonance."},{"cited_title":"Abramowitz, I","cited_arxiv_id":null,"evidence_quote":"This source supplies the non-Hermitian Hamiltonian with complex coupling that the authors use to extract the coherent and dissipative coupling strengths."},{"cited_title":"Chikazumi and C","cited_arxiv_id":null,"evidence_quote":"This reference gives the FVMSW dispersion formula used to identify the higher-order magnon modes."},{"cited_title":"Damon and J","cited_arxiv_id":null,"evidence_quote":"This reference provides the Bessel-function roots used to compute the FVMSW wave vectors."}],"review_version":1}