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arxiv: 2508.06850 · v2 · pith:KL2LYACPnew · submitted 2025-08-09 · 🪐 quant-ph

Nonreciprocal Macroscopic Entanglement through Magnon Squeezing in a Cavity Magnomechanics

Ziyad Imara , Khadija El Anouz , Ilkay Demir , Abderrahim El Allati This is my paper

Pith reviewed 2026-05-19 00:28 UTC · model grok-4.3

classification 🪐 quant-ph
keywords nonreciprocal entanglementmagnon squeezingcavity magnomechanicsmacroscopic entanglementphase reversalhybrid quantum systemsferrimagnetdirectional entanglement
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The pith

Reversing the squeezing phase of magnons produces two distinct configurations for nonreciprocal entanglement among magnons, photons, and phonons.

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

This paper proposes a mechanism to create nonreciprocal macroscopic entanglement in a cavity magnomechanical system by adding a squeezed magnon mode. Reversing the squeezing phase by pi simultaneously reverses the frequency shift and the effective dissipation rate, yielding two experimentally different setups where entanglement becomes direction-dependent. Control over both the amplitude and phase of the squeezed mode provides tunable nonreciprocity, unlike methods that adjust only frequency shifts. The scheme reaches ideal nonreciprocity when cavity-magnon coupling and bath temperature are optimized, and it operates with parameters already accessible in current experiments on ferrimagnets.

Core claim

In the cavity magnomechanics system, magnons arising from collective spin motion in a macroscopic ferrimagnet couple to microwave photons via magnetic dipole interaction and to phonons via magnetostrictive interaction. Introducing a squeezed magnon mode and reversing its squeezing phase from theta to theta plus pi reverses both the frequency shift and the effective dissipation rate at once. This reversal generates two experimentally distinct configurations that support nonreciprocal entanglement among the magnon, photon, and phonon modes. The resulting nonreciprocity can be made ideal and further tuned by the strength of the cavity-magnon coupling and the temperature of the thermal bath.

What carries the argument

The squeezed magnon mode whose phase reversal by pi simultaneously flips the frequency shift and effective dissipation rate to produce nonreciprocal entanglement.

Load-bearing premise

Precise experimental control of both the amplitude and phase of the squeezed magnon mode must be possible while the system continues to be accurately described by the standard cavity-magnon-phonon Hamiltonian plus the added squeezing term.

What would settle it

An experiment in which the frequency shift and effective dissipation rate fail to reverse together when the squeezing phase is shifted by pi would show that the predicted nonreciprocal entanglement does not arise.

Figures

Figures reproduced from arXiv: 2508.06850 by Abderrahim El Allati, Ilkay Demir, Khadija El Anouz, Ziyad Imara.

Figure 1
Figure 1. Figure 1: FIG. 1 [PITH_FULL_IMAGE:figures/full_fig_p002_1.png] view at source ↗
Figure 2
Figure 2. Figure 2: FIG. 2 [PITH_FULL_IMAGE:figures/full_fig_p004_2.png] view at source ↗
Figure 3
Figure 3. Figure 3: FIG. 3 [PITH_FULL_IMAGE:figures/full_fig_p004_3.png] view at source ↗
Figure 5
Figure 5. Figure 5: FIG. 5 [PITH_FULL_IMAGE:figures/full_fig_p005_5.png] view at source ↗
Figure 4
Figure 4. Figure 4: FIG. 4 [PITH_FULL_IMAGE:figures/full_fig_p005_4.png] view at source ↗
Figure 6
Figure 6. Figure 6: FIG. 6 [PITH_FULL_IMAGE:figures/full_fig_p006_6.png] view at source ↗
Figure 7
Figure 7. Figure 7: FIG. 7 [PITH_FULL_IMAGE:figures/full_fig_p007_7.png] view at source ↗
read the original abstract

Cavity magnomechanics has opened a new frontier in quantum electrodynamics, yielding several significant theoretical and experimental results. In this paper, we propose a different theoretical mechanism to achieve nonreciprocal macroscopic entanglement among magnons, photons, and phonons, based on magnon squeezing. Specifically, reversing the squeezing phase, namely theta -> theta + pi reverses the frequency shift and the effective dissipation rate simultaneously, producing two experimentally distinct configurations that enable nonreciprocal entanglement. Indeed, in contrast to conventional approaches that control only frequency shifts, we show how precise control of the amplitude and phase of the squeezed mode allows us to obtain a tunable nonreciprocity of entanglement. The magnons resulting from the collective motion of the spin in a macroscopic ferrimagnet become coupled to the microwave photons via magnetic dipole interaction and to the phonons via magnetostrictive interaction. Moreover, we show that the proposed scheme achieves ideal nonreciprocity, which can be optimized by cavity-magnon coupling and bath temperature control. Finally, by using the parameters that are experimentally feasible with current technologies, this work provides promising perspectives for hybrid magnon-based quantum technologies.

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 proposes a mechanism for nonreciprocal macroscopic entanglement among magnons, photons, and phonons in a cavity magnomechanical system. The central idea is that adding a magnon squeezing term and reversing its phase (θ → θ + π) simultaneously reverses both the frequency shift and the effective dissipation rate, yielding two distinct configurations that produce tunable, ideal nonreciprocity. The scheme is optimized by cavity-magnon coupling strength and bath temperature, and the authors argue that the required parameters are experimentally accessible with current technology.

Significance. If the effective-model derivation is exact, the work supplies a new route to nonreciprocity that exploits both amplitude and phase control of squeezing rather than frequency shifts alone. This could enlarge the toolbox for hybrid magnon-based quantum devices and provide experimentally distinct operating points for entanglement engineering.

major comments (2)
  1. [§4, after Eq. (12)] §4, after Eq. (12): the claim that θ → θ + π reverses both the real (dissipation) and imaginary (frequency) parts of the effective magnon parameters simultaneously is load-bearing for the nonreciprocity result. The manuscript does not explicitly show the diagonalization or adiabatic-elimination steps that confirm this sign flip survives when the squeezing is realized by a parametric drive; counter-rotating terms or modifications to the magnon-phonon coupling at the same order could invalidate the simultaneous reversal.
  2. [§5, Fig. 3] §5, Fig. 3 and surrounding text: the numerical demonstration of ideal nonreciprocity relies on the effective rates derived in §4. Without an independent check that the sign-reversal property holds beyond the linearized regime, the plotted entanglement asymmetry cannot be taken as confirmation of the central mechanism.
minor comments (2)
  1. [Introduction] The abstract and introduction cite several prior cavity-magnomechanics works but omit recent experimental demonstrations of magnon squeezing; adding these references would strengthen the feasibility discussion.
  2. [§2] Notation for the squeezing phase θ is introduced without an explicit definition of its range or the quadrature it controls; a short clarifying sentence would remove ambiguity for readers.

Simulated Author's Rebuttal

2 responses · 0 unresolved

We thank the referee for the careful reading of our manuscript and the constructive comments. We address each major point below and will incorporate clarifications and additional derivations in a revised version to strengthen the presentation of the effective-model derivation and its validity.

read point-by-point responses

  1. Referee: [§4, after Eq. (12)] §4, after Eq. (12): the claim that θ → θ + π reverses both the real (dissipation) and imaginary (frequency) parts of the effective magnon parameters simultaneously is load-bearing for the nonreciprocity result. The manuscript does not explicitly show the diagonalization or adiabatic-elimination steps that confirm this sign flip survives when the squeezing is realized by a parametric drive; counter-rotating terms or modifications to the magnon-phonon coupling at the same order could invalidate the simultaneous reversal.

    Authors: We agree that making the derivation steps explicit will improve clarity. In the revised manuscript we will insert the full sequence: (i) linearization of the parametric-drive Hamiltonian around the magnon steady state, (ii) the rotating-frame transformation that isolates the squeezing term, and (iii) the adiabatic elimination of the fast magnon mode that yields the effective photon-phonon rates. Under the standard rotating-wave approximation (drive detuned by approximately twice the magnon frequency), counter-rotating terms remain off-resonant and do not alter the sign-reversal property. The magnon-phonon magnetostrictive coupling enters at the same perturbative order and is phase-independent, so the simultaneous flip of both the real (dissipation) and imaginary (frequency-shift) parts survives. We will add a short appendix containing these algebraic steps. revision: yes

  2. Referee: [§5, Fig. 3] §5, Fig. 3 and surrounding text: the numerical demonstration of ideal nonreciprocity relies on the effective rates derived in §4. Without an independent check that the sign-reversal property holds beyond the linearized regime, the plotted entanglement asymmetry cannot be taken as confirmation of the central mechanism.

    Authors: We acknowledge that the entanglement plots in Fig. 3 are obtained from the effective master equation. In the revision we will add a supplementary numerical check that solves the full time-dependent master equation (retaining the parametric drive explicitly) for a representative set of parameters inside the validity window of the linearization. This will confirm that the entanglement asymmetry remains close to the ideal nonreciprocal value when the squeezing phase is reversed, thereby providing an independent verification of the mechanism beyond the strict effective-rate approximation. revision: yes

Circularity Check

0 steps flagged

Derivation of nonreciprocal entanglement via magnon squeezing phase reversal is self-contained with no load-bearing reductions to inputs.

full rationale

The paper begins from the standard cavity-magnon-phonon Hamiltonian augmented by an explicit magnon squeezing term parameterized by amplitude and phase theta. It then derives the effective frequency shifts and dissipation rates, demonstrating that theta to theta + pi produces simultaneous sign reversal in both quantities. This sign-flip property follows directly from the algebraic structure of the linearized or effective master equation rather than from any fitted parameter, self-citation chain, or redefinition of the target nonreciprocity. No uniqueness theorem, ansatz smuggling, or renaming of known results is invoked as load-bearing; the nonreciprocity emerges as a calculable consequence of the model equations under experimentally feasible parameters. The derivation therefore remains independent of its own outputs.

Axiom & Free-Parameter Ledger

3 free parameters · 3 axioms · 0 invented entities

The claim rests on standard quantum-optical modeling of the hybrid system plus the assumption that magnon squeezing can be introduced and controlled as an external parameter.

free parameters (3)
  • squeezing phase theta
    Controllable parameter whose reversal produces the sign flip of frequency shift and dissipation rate.
  • cavity-magnon coupling strength
    Tuned to optimize ideal nonreciprocity.
  • bath temperature
    Adjusted to reach ideal nonreciprocity.
axioms (3)
  • domain assumption Magnons couple to microwave photons via magnetic dipole interaction
    Standard interaction in cavity magnomechanics invoked to establish the hybrid system.
  • domain assumption Magnons couple to phonons via magnetostrictive interaction
    Standard interaction in cavity magnomechanics invoked to establish the hybrid system.
  • domain assumption Squeezing can be applied to the magnon mode with controllable amplitude and phase
    Core assumption enabling the proposed nonreciprocity mechanism.

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