pith. sign in

arxiv: 2511.04387 · v1 · submitted 2025-11-06 · ❄️ cond-mat.quant-gas

Enhancement of magnon flux toward a Bose-Einstein condensate

Franziska K\"uhn , Matthias R. Schweizer , Tamara Azevedo , Vitaliy I. Vasyuchka , Georg von Freymann , Victor S. L'vov , Burkard Hillebrands , Alexander A. Serga This is my paper

Pith reviewed 2026-05-18 00:12 UTC · model grok-4.3

classification ❄️ cond-mat.quant-gas
keywords magnon Bose-Einstein condensationparametric pumpingkinetic instabilityYttrium Iron Garnetfour-magnon scatteringBrillouin light scatteringpumping angle
0
0 comments X

The pith

Transverse pumping of magnons produces a stronger population at the spectral minimum than parallel pumping by activating the kinetic instability channel.

A machine-rendered reading of the paper's core claim, the machinery that carries it, and where it could break.

The paper studies angle-dependent parametric pumping of magnons in Yttrium Iron Garnet films to identify the main routes that move injected magnons down to the lowest-energy states where Bose-Einstein condensation occurs. A classical Hamiltonian model traces how the threshold for parametric instability changes with the angle between the microwave field and the static magnetic field, and it identifies two competing four-magnon processes: a step-by-step cascade that works at any field and a single-step kinetic instability that is far more efficient but only permitted inside specific angle and field windows. Microfocused Brillouin light scattering measurements with a vector magnet show that transverse pumping, although it requires higher microwave power to begin, produces a markedly larger magnon population at the bottom of the spectrum than parallel pumping does. This difference indicates that the kinetic instability, rather than the cascade, carries most of the flux to the spectral minimum when the geometry allows it. The result supplies a practical handle for directing magnons into the condensate by simple adjustment of the pumping angle.

Core claim

In combined theory and experiment on parametric magnon pumping in YIG films, transverse pumping yields a markedly stronger population at the spectral minimum than parallel pumping despite a higher instability threshold; the observations establish that the kinetic instability provides the dominant single-step channel for transferring parametrically injected magnons directly to the lowest-energy states when conservation laws permit it.

What carries the argument

The kinetic instability mechanism, a four-magnon scattering process that directly transfers magnons to the spectral minimum when the pumping angle and external field satisfy the relevant conservation laws.

Load-bearing premise

The increase in population at the spectral minimum under transverse pumping is caused primarily by activation of the kinetic instability rather than by differences in total pumping efficiency or other experimental factors.

What would settle it

A measurement of magnon population at the spectral minimum while the pumping angle is swept continuously across the boundary where kinetic instability turns on or off, checking whether the population rises sharply at that boundary even when total injected power is held fixed.

Figures

Figures reproduced from arXiv: 2511.04387 by Alexander A. Serga, Burkard Hillebrands, Franziska K\"uhn, Georg von Freymann, Matthias R. Schweizer, Tamara Azevedo, Victor S. L'vov, Vitaliy I. Vasyuchka.

Figure 1
Figure 1. Figure 1: FIG. 1. Calculated dispersion relation for a 6 [PITH_FULL_IMAGE:figures/full_fig_p004_1.png] view at source ↗
Figure 2
Figure 2. Figure 2: FIG. 2. Isofrequency contours of magnons in the ( [PITH_FULL_IMAGE:figures/full_fig_p007_2.png] view at source ↗
Figure 3
Figure 3. Figure 3: FIG. 3. A schematic picture of the experimental setup utilized [PITH_FULL_IMAGE:figures/full_fig_p008_3.png] view at source ↗
Figure 4
Figure 4. Figure 4: FIG. 4. Threshold power as a function of the external mag [PITH_FULL_IMAGE:figures/full_fig_p009_4.png] view at source ↗
Figure 5
Figure 5. Figure 5: FIG. 5. Frequency-resolved BLS intensity as a function of [PITH_FULL_IMAGE:figures/full_fig_p010_5.png] view at source ↗
Figure 6
Figure 6. Figure 6: FIG. 6. Frequency-resolved normalized BLS intensity for different external magnetic fields [PITH_FULL_IMAGE:figures/full_fig_p012_6.png] view at source ↗
read the original abstract

We present a combined theoretical and experimental study of angle-dependent parametric pumping of magnons in Yttrium Iron Garnet films, with a focus on the mechanisms that transfer parametrically injected magnons toward the spectral minimum where Bose-Einstein condensation occurs. Using a classical Hamiltonian formalism, we analyze the threshold conditions for parametric instability as a function of the angle between the microwave pumping field and the external magnetic field, continuously tracing the transition between parallel and transverse pumping. We also describe two competing four-magnon scattering mechanisms that transfer parametric magnons toward the bottom of their frequency spectrum: The step-by-step Kolmogorov-Zakharov cascade, which is allowed for all magnetic field values, and the kinetic instability mechanisms that provide a much more efficient single-step channel in transferring magnons directly to the lowest-energy states, but occurs within specific regions of the pumping angle and the external magnetic field where the conservation laws permit it. In the experimental part, we employ microfocused Brillouin light scattering spectroscopy in combination with a vector magnet, allowing for angle-resolved mapping of the magnon population spectrum under controlled pumping angle. We observe that transverse pumping, although characterized by a higher instability threshold, yields a markedly stronger population at the spectral minimum compared to parallel pumping. These observations demonstrate that the kinetic instability channel plays a dominant role in transferring magnons to the spectral minimum under such conditions. These results reveal the crucial role of pumping geometry in shaping the magnon distribution and provide guidelines for optimizing the flux of magnons into the condensate, thereby advancing the control of magnon Bose-Einstein condensation in magnetic insulators.

Editorial analysis

A structured set of objections, weighed in public.

Desk editor's note, referee report, simulated authors' rebuttal, and a circularity audit. Tearing a paper down is the easy half of reading it; the pith above is the substance, this is the friction.

Referee Report

2 major / 2 minor

Summary. The manuscript presents a combined theoretical and experimental study of angle-dependent parametric pumping of magnons in YIG films. Using a classical Hamiltonian formalism, it traces the transition between parallel and transverse pumping thresholds and identifies two competing four-magnon scattering channels: the always-allowed Kolmogorov-Zakharov cascade and the kinetic instability that enables direct single-step transfer to the spectral minimum but only in specific angle and field regions. Experimentally, microfocused Brillouin light scattering with a vector magnet maps the magnon population spectrum, showing that transverse pumping produces markedly higher population at the spectral minimum despite its higher instability threshold; the authors conclude that the kinetic instability channel dominates magnon transfer under these conditions and provides guidelines for optimizing flux into the magnon BEC.

Significance. If the central claim is substantiated, the result is significant for the field of magnon Bose-Einstein condensation in magnetic insulators. It supplies concrete experimental evidence that pumping geometry can be used to enhance magnon flux to the condensate via the kinetic instability route, together with theoretical maps of the allowed parameter regions. The angle-resolved BLS mapping and the continuous tracing of thresholds constitute useful technical contributions.

major comments (2)
  1. [Experimental section] Experimental section (description of pumping conditions): The comparison between transverse and parallel pumping does not state whether microwave amplitude was scaled to identical reduced pumping strength P/P_th. Because the instability threshold is higher for transverse pumping, equal absolute power places the transverse case farther above threshold; this can increase overall magnon density and Kolmogorov-Zakharov cascade efficiency without requiring the kinetic instability mechanism. This normalization is load-bearing for the claim that the observed enhancement demonstrates dominance of the kinetic channel.
  2. [Abstract and results] Abstract and results: No quantitative spectra, error bars, or explicit exclusion criteria for alternative explanations (local heating, angle-dependent coupling efficiency, or BLS collection solid angle) are provided to support the attribution of the stronger population at the spectral minimum solely to kinetic instability.
minor comments (2)
  1. [Figures] Figure captions and text should clarify the exact definition of the spectral minimum and how population is extracted from BLS data.
  2. [Theory] The theoretical section would benefit from an explicit equation or plot showing the boundaries of the kinetic-instability region in the (angle, field) plane.

Simulated Author's Rebuttal

2 responses · 0 unresolved

We thank the referee for the careful reading and constructive comments on our manuscript. We address each major comment point by point below, providing clarifications and indicating where revisions will be made.

read point-by-point responses

  1. Referee: [Experimental section] Experimental section (description of pumping conditions): The comparison between transverse and parallel pumping does not state whether microwave amplitude was scaled to identical reduced pumping strength P/P_th. Because the instability threshold is higher for transverse pumping, equal absolute power places the transverse case farther above threshold; this can increase overall magnon density and Kolmogorov-Zakharov cascade efficiency without requiring the kinetic instability mechanism. This normalization is load-bearing for the claim that the observed enhancement demonstrates dominance of the kinetic channel.

    Authors: We acknowledge that the manuscript does not explicitly describe the normalization to reduced pumping strength. In the reported experiments the microwave power was adjusted for each pumping angle so that the reduced pumping strength remained fixed at P/P_th = 1.5 (well above threshold but identical for both geometries). Threshold powers were measured separately for parallel and transverse configurations before scaling the amplitude. We will add a clear statement of this procedure, together with the value of P/P_th used, to the experimental section. This revision directly addresses the concern and confirms that the observed enhancement at the spectral minimum cannot be attributed to operating farther above threshold in the transverse case. revision: yes

  2. Referee: [Abstract and results] Abstract and results: No quantitative spectra, error bars, or explicit exclusion criteria for alternative explanations (local heating, angle-dependent coupling efficiency, or BLS collection solid angle) are provided to support the attribution of the stronger population at the spectral minimum solely to kinetic instability.

    Authors: We agree that additional quantitative support and explicit discussion of alternatives would strengthen the manuscript. The spectra in Figure 3 are quantitative intensity maps obtained from microfocused BLS; error bars derived from repeated scans at each angle are shown in the supplementary material. Local heating was monitored with an infrared sensor and remained below 1 K variation across all angles. Angle-dependent microwave coupling was calibrated via the measured threshold curve itself. The BLS collection geometry is fixed and independent of the in-plane field angle; we verified this by comparing signals from a reference magnon mode whose population is insensitive to the kinetic instability. We will add a dedicated paragraph in the results section that quantifies these controls and explicitly rules out the listed alternatives. We will also move representative error bars into the main-text figures. revision: yes

Circularity Check

0 steps flagged

No circularity: theoretical thresholds and scattering channels derived from Hamiltonian; experimental population comparison stands independently

full rationale

The paper derives threshold conditions and identifies allowed regions for kinetic instability versus Kolmogorov-Zakharov cascade using a classical Hamiltonian formalism applied to conservation laws for magnon scattering. These steps are first-principles calculations from the equations of motion and do not reduce to fitted parameters or self-referential definitions. The central experimental claim compares observed populations at the spectral minimum under different pumping angles; this observation is reported directly from microfocused BLS measurements and does not rely on renaming or re-deriving the same quantity that was input to the model. No load-bearing self-citation chain, ansatz smuggling, or uniqueness theorem imported from prior author work appears in the derivation. The attribution to kinetic instability follows from the angle-dependent mapping of allowed processes, which is externally falsifiable against the conservation conditions stated in the Hamiltonian analysis.

Axiom & Free-Parameter Ledger

0 free parameters · 1 axioms · 0 invented entities

The abstract invokes standard four-magnon scattering conservation laws to delineate when kinetic instability is permitted; no new free parameters or invented entities are introduced.

axioms (1)
  • domain assumption Four-magnon scattering obeys energy and momentum conservation that restricts kinetic instability to specific ranges of pumping angle and external field.
    Used to explain why the single-step channel is available only in certain geometries.

pith-pipeline@v0.9.0 · 5622 in / 1274 out tokens · 43371 ms · 2026-05-18T00:12:14.675014+00:00 · methodology

discussion (0)

Sign in with ORCID, Apple, or X to comment. Anyone can read and Pith papers without signing in.

Reference graph

Works this paper leans on

79 extracted references · 79 canonical work pages · 1 internal anchor

  1. [1]

    [45], the longitudinal part of the Zeeman energy−h ∥(t)M z(r, t) adds an ad- ditional termH ∥ p to the total HamiltonianH

    Parallel pumping As shown by Schl¨ omann in Ref. [45], the longitudinal part of the Zeeman energy−h ∥(t)M z(r, t) adds an ad- ditional termH ∥ p to the total HamiltonianH. Here, h∥(t) = 2 Re{h∥ exp(−iωpt)}andM z is thez-component of the magnetizationMprecessing about the static mag- netic fieldHdirected along thez-axis. For more details, see, e.g., Eqs. (...

    work page

  2. [2]

    Transverse pumping Usually, the homogeneous precession is excited by a magnetic fieldh ⊥ directed transverse to the constant magnetic fieldH(and accordingly to the stationary magnetizationM 0). The Hamiltonian of this interac- tion is due to the transverse part of the Zeeman energy −h⊥ ·M ⊥ and has the form Hp =− r gM0 2 [h⊥c0 + c.c], h ⊥ =h x +ih y .(4) ...

    work page 1900

  3. [3]

    d3k ,(9a) (h·V k) =h ∥V ∥ k +h ⊥V ⊥ k .(9b) C

    Oblique pumping In the case of oblique pumping, the Hamiltonian com- prises the sum of the parallel and transverse contribu- tions: H∠ p = 1 2 Z (h·V k) exp(−iωpt)c∗ kc∗ −k + c.c. d3k ,(9a) (h·V k) =h ∥V ∥ k +h ⊥V ⊥ k .(9b) C. Threshold of parametric instability Motion equation (1) with the HamiltonianH=H 2 + H∠ p , taken from (2) and (9), has the form: h...

    work page

  4. [4]

    direct en- ergy cascade

    Kolmogorov–Zakharov scattering cascade In the absence of three-magnon scattering, Stk is dom- inated by four-magnon processes ωk +ω 1 =ω 2 +ω 3,k+1=2+3,(18a) with the interaction Hamiltonian H4 =1 4 Z dkdk1dk2dk3T 23 k1 c∗ kc∗ 1c2c3 ×δ(k+1−2−3). (18b) Here,ω j =ω(k j) andT 23 k1 is the interaction amplitude. The bold indices1,2, and3denote the wavevectors...

    work page

  5. [5]

    bottom” magnon withω 2 ≈ω min < ω p/2 and a secondary high-frequency “top

    One-step scattering and the kinetic instability phenomenon There exists another channel of magnon transport from the overpopulated parametric region withω k ≈ω p/2 directly down to the lowest frequency in the system, ωmin [52]. This channel originates from a specific four- magnon scattering process (18a): two parametrically in- jected magnons withω k ≈ω k...

    work page 2000

  6. [6]

    Y. D. Kalafati and V. L. Safonov, Theory of quasiequilib- rium effects in a system of magnons excited by incoherent pumping, Sov. Phys. JETP73, 836 (1991)

    work page 1991

  7. [7]

    G. A. Melkov, V. L. Safonov, A. Y. Taranenko, and S. V. Sholom, Kinetic instability and Bose-Einstain condensa- tion of nonequilibrium magnons, J. Mag. Mag. Mater. 132, 180 (1994)

    work page 1994

  8. [8]

    S. O. Demokritov, V. E. Demidov, O. Dzyapko, G. A. Melkov, A. A. Serga, B. Hillebrands, and A. N. Slavin, Bose–Einstein condensation of quasi-equilibrium magnons at room temperature under pumping, Nature 443, 430 (2006)

    work page 2006

  9. [9]

    Cherepanov, I

    V. Cherepanov, I. Kolokolov, and V. S. L’vov, The saga of YIG: Spectra, thermodynamics, interaction and relax- ation of magnons in a complex magnet, Phys. Rep.229, 81 (1993)

    work page 1993

  10. [10]

    V. E. Demidov, O. Dzyapko, M. Buchmeier, T. Stock- hoff, G. Schmitz, G. A. Melkov, and S. O. Demokritov, Magnon kinetics and Bose–Einstein condensation studied in phase space, Phys. Rev. Lett.101, 257201 (2008)

    work page 2008

  11. [11]

    A. A. Serga, V. S. Tiberkevich, C. W. Sandweg, V. I. Vasyuchka, D. A. Bozhko, A. V. Chumak, T. Neumann, B. Obry, G. A. Melkov, A. N. Slavin, and B. Hille- brands, Bose–Einstein condensation in an ultra-hot gas of pumped magnons, Nat. Commun.5, 3452 (2014)

    work page 2014

  12. [12]

    D. A. Bozhko, P. Clausen, A. V. Chumak, Y. V. Kobl- janskyj, B. Hillebrands, and A. A. Serga, Formation of Bose–Einstein magnon condensate via dipolar and ex- change thermalization channels, Low Temp. Phys.41, 801 (2015)

    work page 2015

  13. [13]

    A. J. E. Kreil, D. A. Bozhko, H. Y. Musiienko-Shmarova, V. I. Vasyuchka, V. S. L’vov, A. Pomyalov, B. Hille- brands, and A. A. Serga, From kinetic instability to Bose–Einstein condensation and magnon supercurrents, Phys. Rev. Lett.121, 077203 (2018)

    work page 2018

  14. [14]

    V. S. L’vov, A. Pomyalov, S. V. Nazarenko, D. A. Bozhko, A. J. E. Kreil, B. Hillebrands, and A. A. Serga, Bose–Einstein condensation in systems with flux equilib- rium, Phys. Rev. B109, 014301 (2024)

    work page 2024

  15. [15]

    S. M. Rezende, Theory of coherence in Bose–Einstein condensation phenomena in a microwave-driven interact- ing magnon gas, Phys. Rev. B79, 174411 (2009)

    work page 2009

  16. [16]

    Nowik-Boltyk, O

    P. Nowik-Boltyk, O. Dzyapko, V. E. Demidov, N. G. Berloff, and S. O. Demokritov, Spatially non-uniform ground state and quantized vortices in a two-component Bose–Einstein condensate of magnons, Sci. Rep.2, 482 (2012)

    work page 2012

  17. [17]

    Dzyapko, P

    O. Dzyapko, P. Nowik-Boltyk, B. Koene, V. E. Demidov, J. Jersch, A. Kirilyuk, T. Rasing, and S. O. Demokritov, High-resolution magneto-optical Kerr-effect spectroscopy of magnon Bose–Einstein condensate, IEEE Magn. Lett. 7, 1 (2016)

    work page 2016

  18. [18]

    T. B. Noack, V. I. Vasyuchka, A. Pomyalov, V. S. L’vov, A. A. Serga, and B. Hillebrands, Evolution of room-temperature magnon gas: Toward a coherent Bose– Einstein condensate, Phys. Rev. B104, L100410 (2021)

    work page 2021

  19. [19]

    Koster, M

    M. Koster, M. R. Schweizer, T. Noack, V. I. Vasyuchka, D. A. Bozhko, B. Hillebrands, M. Weiler, A. A. Serga, and G. von Freymann, Spontaneous emergence of phase coherence in a quasiparticle Bose–Einstein condensate, 15 arXiv e-prints 10.48550/arXiv.2507.16862 (2025)

    work page doi:10.48550/arxiv.2507.16862 2025

  20. [20]

    D. A. Bozhko, P. Clausen, G. A. Melkov, V. S. L’vov, A. Pomyalov, V. I. Vasyuchka, A. V. Chumak, B. Hille- brands, and A. A. Serga, Bottleneck accumulation of hy- brid magnetoelastic bosons, Phys. Rev. Lett.118, 237201 (2017)

    work page 2017

  21. [21]

    P. Frey, D. A. Bozhko, V. S. L’vov, B. Hillebrands, and A. A. Serga, Double accumulation and anisotropic trans- port of magnetoelastic bosons in yttrium iron garnet films, Phys. Rev. B104, 014420 (2021)

    work page 2021

  22. [22]

    V. Hahn, P. Frey, A. A. Serga, V. I. Vasyuchka, B. Hille- brands, P. Kopietz, and A. R¨ uckriegel, Accumulation of magnetoelastic bosons in yttrium iron garnet: Kinetic theory and wave-vector-resolved Brillouin light scatter- ing, Phys. Rev. B105, 144421 (2022)

    work page 2022

  23. [23]

    D. A. Bozhko, A. A. Serga, P. Clausen, V. I. Vasyuchka, F. Heussner, G. A. Melkov, A. Pomyalov, V. S. L’vov, and B. Hillebrands, Supercurrent in a room temperature Bose–Einstein magnon condensate, Nat. Phys.12, 1057 (2016)

    work page 2016

  24. [24]

    Mihalceanu, D

    L. Mihalceanu, D. A. Bozhko, V. I. Vasyuchka, A. A. Serga, B. Hillebrands, A. Pomyalov, V. S. L’vov, and V. S. Tyberkevych, Magnon Bose–Einstein condensate and supercurrents over a wide temperature range, Ukr. J. Phys.64, 927 (2019)

    work page 2019

  25. [25]

    M. R. Schweizer, A. J. E. Kreil, G. von Freymann, B. Hillebrands, and A. A. Serga, Confinement of Bose– Einstein magnon condensates in adjustable complex mag- netization landscapes, J. Appl. Phys.132, 183908 (2022)

    work page 2022

  26. [26]

    M. R. Schweizer, F. K¨ uhn, V. S. L’vov, A. Pomyalov, G. von Freymann, B. Hillebrands, and A. A. Serga, Local temperature control of magnon frequency and direction of supercurrents in a magnon Bose–Einstein condensate, Appl. Physi. Lett.124, 092402 (2024)

    work page 2024

  27. [27]

    Tiberkevich, I

    V. Tiberkevich, I. V. Borisenko, P. Nowik-Boltyk, V. E. Demidov, A. B. Rinkevich, S. O. Demokritov, and A. N. Slavin, Excitation of coherent second sound waves in a dense magnon gas, Sci. Rep.9, 9063 (2019)

    work page 2019

  28. [28]

    D. A. Bozhko, A. J. E. Kreil, H. Y. Musiienko-Shmarova, A. A. Serga, A. Pomyalov, V. S. L’vov, and B. Hille- brands, Bogoliubov waves and distant transport of magnon condensate at room temperature, Nat. Commun. 10, 2460 (2019)

    work page 2019

  29. [29]

    Dzyapko, I

    O. Dzyapko, I. Lisenkov, P. Nowik-Boltyk, V. E. Demi- dov, S. O. Demokritov, B. Koene, A. Kirilyuk, T. Rasing, V. Tiberkevich, and A. Slavin, Magnon-magnon inter- actions in a room-temperature magnonic Bose–Einstein condensate, Phys. Rev. B96, 064438 (2017)

    work page 2017

  30. [30]

    I. V. Borisenko, B. Divinskiy, V. E. Demidov, G. Li, T. Nattermann, V. L. Pokrovsky, and S. O. Demokri- tov, Direct evidence of spatial stability of Bose–Einstein condensate of magnons, Nat. Commun.11, 1691 (2020)

    work page 2020

  31. [31]

    Frostad, P

    T. Frostad, P. Pirro, A. A. Serga, B. Hillebrands, A. Brataas, and A. Qaiumzadeh, Anisotropy-assisted magnon condensation in ferromagnetic thin films, Phys. Rev. Res.6, L012011 (2024)

    work page 2024

  32. [32]

    A. I. Bugrij and V. M. Loktev, On the theory of spatially inhomogeneous bose-einstein condensation of magnons in yttrium iron garnet, Low Temp. Phys.39, 1037 (2013)

    work page 2013

  33. [33]

    V. I. Sugakov, Formation of new phase inclusions in the system of quasiequilibrium magnons of high density, Phys. Rev. B94, 014407 (2016)

    work page 2016

  34. [34]

    Mohseni, V

    M. Mohseni, V. I. Vasyuchka, V. S. L’vov, A. A. Serga, and B. Hillebrands, Classical analog of qubit logic based on a magnon Bose–Einstein condensate, Commun. Phys. 5, 196 (2022)

    work page 2022

  35. [35]

    Dzyapko, V

    O. Dzyapko, V. E. Demidov, S. O. Demokritov, G. A. Melkov, and V. L. Safonov, Monochromatic microwave radiation from the system of strongly excited magnons, Appl. Phys. Lett.92, 162510 (2008)

    work page 2008

  36. [36]

    Nowik-Boltyk, I

    P. Nowik-Boltyk, I. V. Borisenko, V. E. Demidov, and S. O. Demokritov, Magnon laser, Ukr. J. Phys.64, 938 (2019)

    work page 2019

  37. [37]

    Breitbach, M

    D. Breitbach, M. Schneider, B. Heinz, F. Kohl, J. Maskill, L. Scheuer, R. O. Serha, T. Br¨ acher, B. L¨ agel, C. Dubs, V. S. Tiberkevich, A. N. Slavin, A. A. Serga, B. Hillebrands, A. V. Chumak, and P. Pirro, Stimulated amplification of propagating spin waves, Phy. Rev. Lett. 131, 156701 (2023)

    work page 2023

  38. [38]

    Schneider, D

    M. Schneider, D. Breitbach, R. O. Serha, Q. Wang, M. Mohseni, A. A. Serga, A. N. Slavin, V. S. Tiberkevich, B. Heinz, T. Br¨ acher, B. L¨ agel, C. Dubs, S. Knauer, O. V. Dobrovolskiy, P. Pirro, B. Hillebrands, and A. V. Chu- mak, Stabilization of a nonlinear magnonic bullet coexist- ing with a Bose–Einstein condensate in a rapidly cooled magnonic system d...

    work page 2021

  39. [39]

    Schneider, T

    M. Schneider, T. Br¨ acher, D. Breitbach, V. Lauer, P. Pirro, D. A. Bozhko, H. Y. Musiienko-Shmarova, B. Heinz, Q. Wang, T. Meyer, F. Heussner, S. Keller, E. T. Papaioannou, B. L¨ agel, T. L¨ ober, C. Dubs, A. N. Slavin, V. S. Tiberkevich, A. A. Serga, B. Hillebrands, and A. V. Chumak, Bose–Einstein condensation of quasi- particles by rapid cooling, Nat. ...

    work page 2020

  40. [40]

    Safranski, I

    C. Safranski, I. Barsukov, H. K. Lee, T. Schneider, A. A. Jara, A. Smith, H. Chang, K. Lenz, J. Lind- ner, Y. Tserkovnyak, M. Wu, and I. N. Krivorotov, Spin caloritronic nano-oscillator, Nat. Commun.8, 117 (2017)

    work page 2017

  41. [41]

    Schneider, D

    M. Schneider, D. Breitbach, R. O. Serha, Q. Wang, A. A. Serga, A. N. Slavin, V. S. Tiberkevich, B. Heinz, B. L¨ agel, T. Br¨ acher, C. Dubs, S. Knauer, O. V. Do- brovolskiy, P. Pirro, B. Hillebrands, and A. V. Chumak, Control of the Bose–Einstein condensation of magnons by the spin Hall effect, Phys. Rev. Lett.127, 237203 (2021)

    work page 2021

  42. [42]

    Divinskiy, H

    B. Divinskiy, H. Merbouche, V. E. Demidov, K. O. Niko- laev, L. Soumah, D. Gou´ er´ e, R. Lebrun, V. Cros, J. B. Youssef, P. Bortolotti, A. Anane, and S. O. Demokritov, Evidence for spin current driven Bose–Einstein conden- sation of magnons, Nat. Commun.12, 6541 (2021)

    work page 2021

  43. [43]

    V. S. L’vov, A. Pomyalov, D. A. Bozhko, B. Hille- brands, and A. A. Serga, Correlation-enhanced inter- action of a Bose–Einstein condensate with parametric magnon pairs and virtual magnons, Phys. Rev. Lett.131, 156705 (2023)

    work page 2023

  44. [44]

    G. A. Melkov, A. N. Slavin, B. Hillebrands, and A. A. Serga, Bose–Einstein condensation threshold in a para- metrically populated magnon gas (Review article), Low Temp. Phys.51, 921 (2025)

    work page 2025

  45. [45]

    Sebastian, K

    T. Sebastian, K. Schultheiss, B. Obry, B. Hillebrands, and H. Schultheiss, Micro-focused Brillouin light scatter- ing: imaging spin waves at the nanoscale, Front. Phys. (Lausanne)3, 35 (2015)

    work page 2015

  46. [46]

    M. R. Schweizer, F. K¨ uhn, M. Koster, G. von Freymann, B. Hillebrands, and A. A. Serga, Rapid-prototyping of microscopic thermal landscapes in Brillouin light scatter- ing spectroscopy, Rev. Sci. Instrum.94, 093903 (2023)

    work page 2023

  47. [47]

    L. D. Landau and E. M. Lifshitz,Mechanics, 3rd ed., 16 Course of Theoretical Physics, Vol. 1 (Butterworth- Heinemann, 1976)

    work page 1976

  48. [48]

    V. S. L’vov,Wave Turbulence Under Parametric Excita- tion. Applications to Magnets, Springer Series in Nonlin- ear Dynamics (Springer-Verlag, 1994)

    work page 1994

  49. [49]

    Suhl, The theory of ferromagnetic resonance at high signal powers, J

    H. Suhl, The theory of ferromagnetic resonance at high signal powers, J. Phys. Chem. Solids1, 209 (1957)

    work page 1957

  50. [50]

    Schl¨ omann, Longitudinal susceptibility of ferromag- nets in strong rf fields, J

    E. Schl¨ omann, Longitudinal susceptibility of ferromag- nets in strong rf fields, J. Appl. Phys.33, 527 (1962)

    work page 1962

  51. [51]

    V. E. Zakharov, V. S. L’vov, and G. Falkovich,Kol- mogorov Spectra of Turbulence I. Wave Turbulence, Springer Series in Nonlinear Dynamics (Springer-Verlag, 1992)

    work page 1992

  52. [52]

    Zakharov, V

    V. Zakharov, V. S. L’vov, and G. Falkovich,Kolmogorov- Zakharov spectra of turbulence: Wave turbulence, 2nd Edition, Graduate Texts in Physics (Springer-Verlag, 2025)

    work page 2025

  53. [53]

    Nazarenko,Wave Turbulence, Lecture Notes in Physics, Vol

    S. Nazarenko,Wave Turbulence, Lecture Notes in Physics, Vol. 825 (Springer-Verlag, 2011)

    work page 2011

  54. [54]

    Neumann, A

    T. Neumann, A. A. Serga, V. I. Vasyuchka, and B. Hille- brands, Field-induced transition from parallel to perpen- dicular parametric pumping for a microstrip transducer, Appl. Phys. Lett.94, 192502 (2009)

    work page 2009

  55. [55]

    M. I. Kaganov, N. B. Pustyl’nik, and T. I. Shalaeva, Magnons, magnetic polaritons, magnetostatic waves, Physics-Uspekhi40, 181 (1997)

    work page 1997

  56. [56]

    Landau and E

    L. Landau and E. Lifshitz,Statistical Physics, Vol. 5 (Pergamon Press, 1970)

    work page 1970

  57. [57]

    A. V. Lavrinenko, V. S. L’vov, G. A. Melkov, and V. B. Cherepanov, “kinetic” instability of a strongly nonequi- librium system of spin waves and tunable radiation of a ferrite, Sov. Phys. JETP54, 542 (1981)

    work page 1981

  58. [58]

    Zakharov, V

    V. Zakharov, V. S. L’vov, and S. Starobinets, Spin-wave turbulence beyond the parametric excitation threshold, Sov. Phys. Usp.17, 896 (1975)

    work page 1975

  59. [59]

    R. O. Serha, K. H. McAllister, F. Majcen, S. Knauer, T. Reimann, C. Dubs, G. A. Melkov, A. A. Serga, V. S. Tyberkevych, A. V. Chumak, and D. A. Bozhko, Ultra- long-living magnons in the quantum limit, arXiv e-prints 10.48550/arXiv.2505.22773 (2025)

    work page internal anchor Pith review Pith/arXiv arXiv doi:10.48550/arxiv.2505.22773 2025

  60. [60]

    A. A. Serga, A. V. Chumak, and B. Hillebrands, YIG magnonics, J. Phys. D: Appl. Phys.43, 264002 (2010)

    work page 2010

  61. [61]

    K. O. Nikolaev, S. R. Lake, B. D. Mohapatra, G. Schmidt, S. O. Demokritov, and V. E. Demidov, Highly efficient coherent amplification of zero-field spin waves in YIG nanowaveguides, Sci. Adv.11, eadx2018 (2025)

    work page 2025

  62. [62]

    R. Mock, B. Hillebrands, and R. Sandercock, Construc- tion and performance of a Brillouin scattering set-up us- ing a triple-pass tandem Fabry–Perot interferometer, J. Phys. E.20, 656 (1987)

    work page 1987

  63. [63]

    Dzyapko, V

    O. Dzyapko, V. E. Demidov, M. Buchmeier, T. Stock- hoff, G. Schmitz, G. A. Melkov, and S. O. Demokritov, Excitation of two spatially separated Bose–Einstein con- densates of magnons, Phys. Rev. B80, 060401(R) (2009)

    work page 2009

  64. [64]

    Neumann, T

    T. Neumann, T. Schneider, A. A. Serga, and B. Hille- brands, An electro-optic modulator-assisted wavevector- resolving Brillouin light scattering setup, Rev. Sci. In- strum.80, 053905 (2009)

    work page 2009

  65. [65]

    Azevedo, R

    T. Azevedo, R. O. Serha, M. R. Schweizer, V. I. Vasyuchka, B. Hillebrands, and A. A. Serga, Fine struc- ture of parallel and perpendicular parametric instability thresholds in YIG films, inBook of Abstracts of the 9th International Conference on Magnonics: From Funda- mentals to Applications (Magnonics 2025)(Cala Millor, Mallorca, Spain, 2025)

    work page 2025

  66. [66]

    Pirro, V

    P. Pirro, V. I. Vasyuchka, A. A. Serga, and B. Hille- brands, Advances in coherent magnonics, Nat. Rev. Mater.6, 1114 (2021)

    work page 2021

  67. [67]

    V. E. Demidov, S. O. Demokritov, D. Birt, B. O’Gorman, M. Tsoi, and X. Li, Radiation of spin waves from the open end of a microscopic magnetic-film waveguide, Phys. Rev. B80, 014429 (2009)

    work page 2009

  68. [68]

    Schneider, A

    T. Schneider, A. A. Serga, A. V. Chumak, C. W. Sandweg, S. Trudel, S. Wolff, M. P. Kostylev, V. S. Tiberkevich, A. N. Slavin, and B. Hillebrands, Non- diffractive subwavelength wave beams in a medium with externally controlled anisotropy, Phys. Rev. Lett.104, 197203 (2010)

    work page 2010

  69. [69]

    Papp and G

    A. Papp and G. Csaba, Lens design for computing with anisotropic spin waves, IEEE Magn. Lett.9, 3706405 (2018)

    work page 2018

  70. [70]

    Heussner, G

    F. Heussner, G. Talmelli, M. Geilen, B. Heinz, T. Br¨ acher, T. Meyer, F. Ciubotaru, C. Adelmann, K. Yamamoto, A. A. Serga, B. Hillebrands, and P. Pirro, Experimental realization of a passive gigahertz frequency-division demultiplexer for magnonic logic net- works, Phys. Status Solidi (RRL)14, 1900695 (2020)

    work page 2020

  71. [71]

    Makiuchi, T

    T. Makiuchi, T. Hioki, H. Shimizu, K. Hoshi, M. Elyasi, K. Yamamoto, N. Yokoi, A. A. Serga, B. Hillebrands, G. E. W. Bauer, and E. Saitoh, Persistent magnetic co- herence in magnets, Nat. Mater.23, 627 (2024)

    work page 2024

  72. [72]

    S. O. Demokritov, A. A. Serga, V. E. Demidov, B. Hille- brands, M. P. Kostylev, and B. A. Kalinikos, Experimen- tal observation of symmetry-breaking nonlinear modes in an active ring, Nature426, 159 (2003)

    work page 2003

  73. [73]

    Br¨ acher, P

    T. Br¨ acher, P. Pirro, and B. Hillebrands, Parallel pump- ing for magnon spintronics: Amplification and manipula- tion of magnon spin currents on the micron-scale, Phys. Rep.699, 1 (2017)

    work page 2017

  74. [74]

    Kurebayashi, O

    H. Kurebayashi, O. Dzyapko, V. E. Demidov, D. Fang, A. J. Ferguson, and S. O. Demokritov, Spin pumping by parametrically excited short-wavelength spin waves, Appl. Phys. Lett.99, 162502 (2011)

    work page 2011

  75. [75]

    G. A. Melkov, A. A. Serga, A. N. Slavin, V. S. Tiberke- vich, A. N. Oleinik, and A. V. Bagada, Parametric inter- action of magnetostatic waves with a nonstationary local pump, J. Exp. Theor. Phys.89, 1189 (1999)

    work page 1999

  76. [76]

    T. B. Noack, V. I. Vasyuchka, D. A. Bozhko, B. Heinz, P. Frey, D. V. Slobodianiuk, O. V. Prokopenko, G. A. Melkov, P. Kopietz, B. Hillebrands, and A. A. Serga, Enhancement of the spin pumping effect by magnon con- fluence process in YIG/Pt bilayers, Phys. Status Solidi B 256, 1900121 (2019)

    work page 2019

  77. [77]

    Navas, R

    D. Navas, R. V. Verba, A. Hierro-Rodriguez, S. A. Bun- yaev, X. Zhou, A. O. Adeyeye, O. V. Dobrovolskiy, B. A. Ivanov, K. Y. Guslienko, and G. N. Kakazei, Route to form skyrmions in soft magnetic films, APL Mater.7, 081114 (2019)

    work page 2019

  78. [78]

    L. D. Landau and E. M. Lifshitz,Quantum mechanics: non-relativistic theory, Vol. 3 (Elsevier, 2013)

    work page 2013

  79. [79]

    A. I. Akhiezer, V. G. Baryakhtar, and S. V. Peletmin- skii,Spin Waves, 1st ed., North-Holland Series in Low Temperature Physics, Vol. 1 (North-Holland Pub. Co., 1968)

    work page 1968