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Towards Magnetic Field Quantum Memory: A Theoretical Framework for Frequency-Addressed Data Storage Using Quantum Superposition and P-Wave Magnetis

Marco Glamngiw

Published Feb 1, 2026• 0 citations
Publisher

Abstract

We propose a theoretical framework for quantum data storage based on magnon modes in magnetic media, with frequency-based addressing implemented through quantum superposition states. Unlike conventional memory architectures that rely on fixed spatial positions, the proposed approach encodes logical addresses in mode structure, reducing dependence on absolute spatial coordinates. We analyze the system within a mode-resolved Hamiltonian formalism and show that the number of independently addressable channels is fundamentally limited by spectral linewidth (Γ) and available bandwidth. Coherent signal accumulation exhibits an ideal N² scaling in the fully phase-locked limit, though practical implementations are expected to be linewidth- and decoherence-limited. Photon–magnon coupling provides a physically grounded mechanism for state transfer between optical and magnetic degrees of freedom. Additionally, recently reported p-wave magnetic structures in NiI₂ may offer a potential platform for exploring mode-defined frequency channels, although coherent storage in such materials remains experimentally unverified. This work defines quantitative operating limits and proposes falsifiable criteria for experimental validation. Keywords: quantum memory, magnon modes, linewidth-limited addressing, photon–magnon coupling, mode-based storage

DOI
10.5281/zenodo.18451270

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We propose a theoretical framework for quantum data storage based on magnon modes in magnetic media, with frequency-based addressing implemented through quantum superposition states. Unlike conventional memory architectures that rely on fixed spatial positions, the proposed approach encodes logical addresses in mode structure, reducing dependence on absolute spatial coordinates. We analyze the system within a mode-resolved Hamiltonian formalism and show that the number of independently addressable channels is fundamentally limited by spectral linewidth (Γ) and available bandwidth. Coherent signal accumulation exhibits an ideal N² scaling in the fully phase-locked limit, though practical implementations are expected to be linewidth- and decoherence-limited. Photon–magnon coupling provides a physically grounded mechanism for state transfer between optical and magnetic degrees of freedom. Additionally, recently reported p-wave magnetic structures in NiI₂ may offer a potential platform for exploring mode-defined frequency channels, although coherent storage in such materials remains experimentally unverified. This work defines quantitative operating limits and proposes falsifiable criteria for experimental validation. Keywords: quantum memory, magnon modes, linewidth-limited addressing, photon–magnon coupling, mode-based storage
This paper analyzes fundamental physical constraints on magnon-based quantum memory systems. We examine collective-mode behavior and magnetohydrodynamic (MHD) limits that govern the scalability of photon-magnon quantum state transfer. Key findings: - Spin wave propagation limits spatial addressing resolution - Magnetic Reynolds number R_m ≈ 10⁻¹² confirms diffusion-dominated regime - Maximum achievable channels: N_max ~ 10³-10⁴ via frequency-based addressing - Channel crosstalk analysis provides design guidelines This work complements the theoretical framework (Paper I) and experimental proposal (Paper II) in a three-paper series on magnetic quantum memory. Keywords: quantum memory, magnons, spin waves, magnetohydrodynamics, photon-magnon coupling
Abstract Ensemble-based quantum memories are key to developing multiplexed quantum repeaters, able to overcome the intrinsic rate limitation imposed by finite communication times over long distances. Rare-earth ion doped crystals are main candidates for highly multimode quantum memories, where time, frequency and spatial multiplexing can be exploited to store multiple modes. In this context the atomic frequency comb (AFC) quantum memory provides large temporal multimode capacity, which can readily be combined with multiplexing in frequency and space. In this article, we derive theoretical formulas for quantifying the temporal multimode capacity of AFC-based memories, for both optical memories with fixed storage time and spin-wave memories with longer storage times and on-demand read out. The temporal multimode capacity is expressed in key memory parameters, such as AFC bandwidth, fixed-delay storage time, memory efficiency, and control field Rabi frequency. Current experiments in europium- and praseodymium-doped Y2SiO5 are analyzed within this theoretical framework, which is also tested with newly acquired data, as prospects for higher temporal capacity in these materials are considered. In addition we consider the possibility of spectral and spatial multiplexing to further increase the mode capacity, with examples given for praseodymium doped Y2SiO5.
I will introduce the fundamental requirements for practically linking quantum objects into large-scale coherent quantum systems as well as the advantages of coherent magnonics for next-generation quantum coherent systems (i.e., spin-entangling quantum gates). Other critical challenges for quantum information science then will motivate the development of coherent magnonics for quantum transduction from “stationary” spin systems to “flying” magnons and for quantum memory. Finally, the advantages of all-magnon quantum information technologies that rely on manipulating and encoding quantum information in superpositions of fixed magnon number states will highlight the potential of new magnetic materials, devices, and systems.
We propose a minimal experimental test to validate photon-magnon quantum state transfer for memory applications. Using established YIG-cavity technology, we demonstrate single-channel quantum addressing with one bit of information. Success criteria: coherence > 1 microsecond, fidelity > 50%. Estimated cost: $50-100k with existing infrastructure. This proposal is a companion to: "Towards Magnetic Field Quantum Memory" (Glamngiw, 2026), DOI: 10.5281/zenodo.18451271 Keywords: photon-magnon coupling, quantum memory, experimental proposal, YIG cavity, coherenc
Quantum mechanics is leading to many modern technologies, e.g. based on laser physics. Emerging fields are for example nonlinear optics, hybrid systems, or quantum communication. Despite these applications, there are still limitations of our understanding of quantum mechanics. Even though it is broadly accepted that decoherence limits the size of entangled states, we currently do not know how to overcome these limitations. How large can commonly entangled states be? Can we observe macroscopic quantum phenomena with coarse-grained detectors or even with our bare eyes? This thesis contributes towards answering these fundamental questions and to technological advances. The experiments are based on a light-matter platform of quantum optical states and atomic ensembles. The ensembles consist of rare-earth ion-doped crystals. Additionally, the atomic frequency comb protocol turns the ensemble into a quantum memory. In the scope of quantum communication we work on a quantum repeater. First, we investigate fundamental quantum mechanical states and their validity at macroscopic scales. We show that the detection of a collectively emitted excitation can be used to measure the size of the entangled ensemble. The entangled ensemble shared this excitation in a coherent superposition. This superposition of an atomic excitation in an ensemble is called W-state. We certify a new lower bound to the possible size of an entangled W-state between at least 16 million atoms. The proof of entanglement of this size relies on two measures: one determines the number of atoms involved in the storage process. The other one determines the state "quantumness" by examining the re-emitted light. Another experiment studies a macroscopically distinguishable superposition state. The superposition survives the storage in an atomic ensemble. Second, we perform two more experiments that contribute to a quantum repeater. One experiment probes the quantum states simultaneously stored in a multi-mode quantum memory. In this work we also develop the concept of indirect entanglement witness. For the other experiment, a frequency down-conversion platform is set up. The conversion overcomes the wavelength compatibility issue between some quantum memories and the telecommunication C-band. The narrow spectral filtering of the conversion performs better than expected. In summary, our work analyzes large entangled states and building blocks for a quantum repeater. The presented quantum memories are capable of temporal multi-mode storage. Its temporally precise re-emission is due to the re-phasing of the atoms of the W-state. We also show a good way to set up frequency down-conversion for the sake of quantum repeaters. This work emphasizes the atomic frequency comb protocol as a viable and reliable platform for quantum repeaters.
This paper proposes a novel approach to data storage leveraging the phenomenon of quantum decoherence. Traditional data storage methods face inherent limitations due to physical constraints on density. This research explores the potential of utilizing quantum decoherence to achieve ultra-high density data storage, enabling rapid read and write operations. The core concept involves encoding information within quantum bits (qubits) through controlled interactions and exploiting the decoherence process itself as a mechanism for both data storage and retrieval. Specifically, we investigate methods for manipulating qubit entanglement and utilizing the loss of coherence as a means of representing data states. The proposed framework aims to surpass the limitations of classical storage, offering a fundamentally different paradigm for information density. The theoretical framework presented here demonstrates the feasibility of this approach, outlining key considerations for qubit control, measurement techniques, and error mitigation strategies. Further research will focus on experimental validation and scaling this technology for practical applications. ---