Challenges
Datasets
Workspaces
Papers
Discussions
Leaderboard
Log inSign up
Challenges
Datasets
Workspaces
Papers
Discussions
Leaderboard
Blog
Job Board
Q3AS

© 2026 Aqora Quantum S.A.S.

TermsPrivacyLegal Notice

arXiv:2511.06324

Magnetic and structural properties of epitaxial Er-substituted yttrium iron garnet films grown by pulsed laser deposition

Lukas Flajsman, Lars Peeters, Armi Kosunen, Lide Yao, Ionela Vrejoiu, Sebastiaan van Dijken

cond-mat.mtrl-sciquant-phSubmitted Nov 9, 2025• Announced Nov 11, 2025
arXivHTMLPDF

Abstract

Er-substituted yttrium iron garnet (Er:YIG) holds the potential of combining the low magnetic damping of YIG with the telecom-band optical transitions of $\text{Er}^{3+}$ ions, making it a suitable material for hybrid optomagnonic devices and microwave-to-optical quantum transduction. We report the epitaxial growth of $\text{Er}_{x}\text{Y}_{3-x}\text{Fe}_{5}\text{O}_{12}$ films with $x=0.008-0.20$ on (111)-oriented gadolinium gallium garnet (GGG) substrates using pulsed laser deposition. X-ray diffraction, reciprocal space mapping, and scanning transmission electron microscopy confirm single-phase, fully coherent growth with atomically sharp interfaces across the entire substitution range. Magnetometry reveals a gradual decrease in saturation magnetization with increasing Er content, consistent with antiparallel coupling between Er$^{3+}$ spins and the net Fe$^{3+}$ moments, along with the emergence of an in-plane uniaxial magnetic anisotropy. The ferromagnetic resonance broadens with Er concentration due to increased Gilbert damping and inhomogeneous linewidth broadening. Films with low Er content ($x=0.008$), most relevant for optomagnonic applications, retain nearly isotropic magnetization and exhibit a damping parameter only slightly higher than that of undoped YIG. These results identify growth and substitution conditions that preserve YIG's low-loss magnetic properties while introducing optical functionality, establishing Er:YIG as a viable platform for hybrid quantum magnonics and microwave-to-optical transduction.

Comments
5 pages, 3 figures, 1 table

Related papers

Magnon-Erbium-Ion Hybrids for Quantum Frequency Conversion

Aliya Galimova, Hasan Pişkin, Faik A. Mikailzade +3 more

In this work, an approach based on the use of yttrium iron garnet (YIG) to increase the efficiency of quantum frequency conversion has been theoretically studied. YIG, which is a ferrimagnetic insulator transparent to both microwave and optical frequencies, has a very low damping parameter. Therefore, the coupling of YIG to microwave resonator modes is very strong. It has been demonstrated that it is possible to use the spin-wave oscillations of YIG to increase essentially the coupling of microwave photons to$\text{Er}^{3+}$spin-flip transitions. The basic parameters of 2 -stage microwave-to-optic transduction in the proposed Erbium-YIG-based Hybrid Quantum System have been theoretically analyzed. The conditions needed for efficient coupling between magnetic resonance levels of$\text{Er}^{3+}$ions and spin wave modes have been also considered.

Photonics & Electromagnetics Research Symposium - Spring (PIERS-Spring)•May 4, 2025•1 citation

Micrometer thick single crystal iron-garnet films on a diamagnetic buffer layer for cryogenic applications

A. N. Kuzmichev, P. M. Vetoshko, E. I. Pavluk +8 more

This work advances the frontier of low-damping magnetic materials, directly addressing the demand for ultra-low-loss components in quantum computing and cryogenic electronics. Here we demonstrate a new approach to get single crystal micrometer-thick yttrium iron garnet (YIG) films with low damping through isolating and mitigating interfacial paramagnetic contributions of a paramagnetic substrate by a buffer-layer. The YIG films with the diamagnetic yttrium scandium gallium garnet buffer layer grown by liquid phase epitaxy on a gadolinium gallium substrate demonstrate homogeneity unprecedented for the thin planar YIG structures, yielding ferromagnetic resonance linewidths of 4.9 MHz at 4 K and 5.9 MHz at 16 mK, the lowest values reported to date. These results underscore the critical role of interfacial engineering in overcoming intrinsic material limitations, opening avenues for further optimization in spin-based technologies.

cond-mat.mtrl-sciCross-listedarXiv:2511.19104•Nov 25, 2025

Applications and Significance of Magneto-Optical Garnets in Quantum Computing and the Quantum Internet

Mehmet Keçeci

Applications and Significance of Magneto-Optical Garnets in Quantum Computing and the Quantum Internet Mehmet Keçeci Orcid: https://orcid.org/0000-0001-9937-9839 Abstract: Magneto-optical garnets, and in particular yttrium iron garnet (YIG, Y₃Fe₅O₁₂), have emerged as a critical interface material in quantum information processing technologies. Superconducting qubits typically operate with microwave photons in the gigahertz regime, whereas long-distance quantum communication relies on visible or near-infrared photons propagating through optical fibres. The ability to coherently link these two fundamentally different physical platforms constitutes a prerequisite for scalable quantum computing architectures and a global quantum internet. Owing to their exceptionally low magnetic damping, high spin density, optical transparency in the near-infrared window, and pronounced Faraday effect, YIG and related garnet compounds provide a versatile hybrid platform that supports coherent quantum state transfer among microwave photons, optical photons, phonons, and superconducting qubits. In this work we review the fundamental physical properties of magneto-optical garnets, their roles in quantum magnonics and optomagnonics, their potential for microwave-to-optical quantum transduction, their functionality in optical isolation and nonreciprocal photonic devices, and the principal technological limitations that currently constrain their performance. We further assess the strategic significance of these materials for distributed quantum computing and quantum internet architectures. Keywords: magneto-optical, garnet, YIG, quantum magnonics, quantum transduction, quantum internet, superconductingqubit, optical isolator, nanostructures, yttrium.

•Oct 12, 2026•0 citations

Controlled growth of rare-earth-doped TiO$_{2}$ thin films on III-V semiconductors for hybrid quantum photonic interfaces

Henry C. Hammer, Caleb Whittier, Nathan A. Helvy +3 more

Quantum photonic networks require two distinct functionalities: bright single-photon sources and long-lived quantum memories. III-V semiconductor quantum dots excel as deterministic and coherent photon emitters, while rare-earth ions such as erbium (Er$^{3+}$) in crystalline oxides offer exceptional spin and optical coherence at telecom wavelengths. Combining these systems and their functionalities via direct epitaxy is challenging due to lattice mismatch and incompatible growth conditions. Here we demonstrate low-temperature pulsed laser deposition of Er$^{3+}$-doped TiO$_{2}$ thin films directly on GaAs and GaSb substrates. Controlled surface preparation with an arsenic cap and an oxygen-deficient buffer layer enables the growth of epitaxial anatase TiO$_{2}$ (001) at 390$^{o}$C with sub-300 pm surface roughness, while avoiding interface degradation. In contrast, high-temperature oxide desorption or growth temperatures drive the transition to rough, polycrystalline rutile film, as confirmed by transmission electron microscopy. Minimal coincident interface area (MCIA) modeling explains the orientation-selective growth on GaAs and GaSb. Raman and cryogenic photoluminescence excitation spectroscopy verify the crystal phase and optical activation of Er$^{3+}$ ions. This multi-parameter growth strategy helps preserve III-V quantum dot functionality and yields smooth surfaces suitable for low-loss nanophotonic structures. Our results establish a materials platform for monolithically integrating rare-earth quantum memories with semiconductor photon sources, paving the way toward scalable hybrid quantum photonic chips.

quant-pharXiv:2511.03918•ACS Applied Optical Materials•Nov 7, 2025•1 citation

Optical Properties of Ho3+ Ions in Yttrium Gallium Garnet and Yttrium Iron Garnet

L. F. Johnson, J. F. Dillon, J. P. Remeika

Optical absorption and emission spectra are used to determine the energy levels of the $^{5}I_{8}$ ground state and $^{5}I_{7}$ excited state of ${\mathrm{Ho}}^{3+}$ in diamagnetic yttrium gallium garnet (YGaG) and ferrimagnetic yttrium iron garnet (YIG). The results for YGaG are consistent with the ${D}_{2}$ site symmetry of the dodecahedral site in the garnet structure. Energy levels in YIG which are separated by site inequivalency are identified from spectra observed as the ${\mathrm{Fe}}^{3+}$ magnetization is rotated in the ($1\overline{1}0$) plane. Stimulated emission is observed from ${\mathrm{Ho}}^{3+}$ in YGaG at 2.086 and 2.114 \ensuremath{\mu} and from ${\mathrm{Ho}}^{3+}$ in YIG at 2.086, 2.089, and 2.107 \ensuremath{\mu}. Each of the lines in YIG is composed of two superimposed electronic transitions. The exchange field in YIG makes possible magnetic tuning of coherent emission over a range of 70 \AA{}.

Physical review. B, Solid state•Mar 1, 1970•31 citations

Epitaxial Er-doped Y2O3 on silicon for quantum coherent devices

Manish Kumar Singh, Abhinav Prakash, Gary Wolfowicz +6 more

Rare-earth ions (REIs) have incomplete 4f shells and possess narrow optical intra-4f transitions due to shielding from electrons in the 5s and 5p orbitals, making them good candidates for solid-state optical quantum memory. The emission of Er3+ in the telecom C-band (1530 nm–1565 nm) makes it especially attractive for this application. In order to build practical, scalable devices, the REI needs to be embedded in a non-interacting host material, preferably one that can be integrated with silicon. In this paper, we show that Er3+ can be isovalently incorporated into epitaxial Y2O3 thin films on Si (111). We report on the synthesis of epitaxial, single-crystalline Er:Y2O3 on Si with a narrow inhomogeneous linewidth in the photoluminescence (PL) spectra, 5.1 GHz (<100 mK), and an optical excited state lifetime of 8.1 ms. The choice of Y2O3 was driven by its low nuclear spin and small lattice mismatch with Si. Using PL and electron paramagnetic resonance, we show that Er3+ substitutes for Y in the crystal lattice. The role of interfacial SiOx, diffusion of silicon into the film, and the effect of buffer layers on the inhomogeneous PL linewidth are examined. We also find that the linewidth decreased monotonically with film thickness but surprisingly exhibits no correlation with the film crystalline quality, as measured by the x-ray rocking curve scans, suggesting other factors at play that limit the inhomogeneous broadening in Y2O3 films.

APL Materials•Mar 1, 2020•56 citations
Er-substituted yttrium iron garnet (Er:YIG) holds the potential of combining the low magnetic damping of YIG with the telecom-band optical transitions of Er3+\text{Er}^{3+}Er3+ ions, making it a suitable material for hybrid optomagnonic devices and microwave-to-optical quantum transduction. We report the epitaxial growth of ErxY3−xFe5O12\text{Er}_{x}\text{Y}_{3-x}\text{Fe}_{5}\text{O}_{12}Erx​Y3−x​Fe5​O12​ films with x=0.008−0.20x=0.008-0.20x=0.008−0.20 on (111)-oriented gadolinium gallium garnet (GGG) substrates using pulsed laser deposition. X-ray diffraction, reciprocal space mapping, and scanning transmission electron microscopy confirm single-phase, fully coherent growth with atomically sharp interfaces across the entire substitution range. Magnetometry reveals a gradual decrease in saturation magnetization with increasing Er content, consistent with antiparallel coupling between Er3+^{3+}3+ spins and the net Fe3+^{3+}3+ moments, along with the emergence of an in-plane uniaxial magnetic anisotropy. The ferromagnetic resonance broadens with Er concentration due to increased Gilbert damping and inhomogeneous linewidth broadening. Films with low Er content (x=0.008x=0.008x=0.008), most relevant for optomagnonic applications, retain nearly isotropic magnetization and exhibit a damping parameter only slightly higher than that of undoped YIG. These results identify growth and substitution conditions that preserve YIG's low-loss magnetic properties while introducing optical functionality, establishing Er:YIG as a viable platform for hybrid quantum magnonics and microwave-to-optical transduction.
In this work, an approach based on the use of yttrium iron garnet (YIG) to increase the efficiency of quantum frequency conversion has been theoretically studied. YIG, which is a ferrimagnetic insulator transparent to both microwave and optical frequencies, has a very low damping parameter. Therefore, the coupling of YIG to microwave resonator modes is very strong. It has been demonstrated that it is possible to use the spin-wave oscillations of YIG to increase essentially the coupling of microwave photons toEr3+\text{Er}^{3+}Er3+spin-flip transitions. The basic parameters of 2 -stage microwave-to-optic transduction in the proposed Erbium-YIG-based Hybrid Quantum System have been theoretically analyzed. The conditions needed for efficient coupling between magnetic resonance levels ofEr3+\text{Er}^{3+}Er3+ions and spin wave modes have been also considered.
This work advances the frontier of low-damping magnetic materials, directly addressing the demand for ultra-low-loss components in quantum computing and cryogenic electronics. Here we demonstrate a new approach to get single crystal micrometer-thick yttrium iron garnet (YIG) films with low damping through isolating and mitigating interfacial paramagnetic contributions of a paramagnetic substrate by a buffer-layer. The YIG films with the diamagnetic yttrium scandium gallium garnet buffer layer grown by liquid phase epitaxy on a gadolinium gallium substrate demonstrate homogeneity unprecedented for the thin planar YIG structures, yielding ferromagnetic resonance linewidths of 4.9 MHz at 4 K and 5.9 MHz at 16 mK, the lowest values reported to date. These results underscore the critical role of interfacial engineering in overcoming intrinsic material limitations, opening avenues for further optimization in spin-based technologies.
Applications and Significance of Magneto-Optical Garnets in Quantum Computing and the Quantum Internet Mehmet Keçeci Orcid: https://orcid.org/0000-0001-9937-9839 Abstract: Magneto-optical garnets, and in particular yttrium iron garnet (YIG, Y₃Fe₅O₁₂), have emerged as a critical interface material in quantum information processing technologies. Superconducting qubits typically operate with microwave photons in the gigahertz regime, whereas long-distance quantum communication relies on visible or near-infrared photons propagating through optical fibres. The ability to coherently link these two fundamentally different physical platforms constitutes a prerequisite for scalable quantum computing architectures and a global quantum internet. Owing to their exceptionally low magnetic damping, high spin density, optical transparency in the near-infrared window, and pronounced Faraday effect, YIG and related garnet compounds provide a versatile hybrid platform that supports coherent quantum state transfer among microwave photons, optical photons, phonons, and superconducting qubits. In this work we review the fundamental physical properties of magneto-optical garnets, their roles in quantum magnonics and optomagnonics, their potential for microwave-to-optical quantum transduction, their functionality in optical isolation and nonreciprocal photonic devices, and the principal technological limitations that currently constrain their performance. We further assess the strategic significance of these materials for distributed quantum computing and quantum internet architectures. Keywords: magneto-optical, garnet, YIG, quantum magnonics, quantum transduction, quantum internet, superconductingqubit, optical isolator, nanostructures, yttrium.
Controlled growth of rare-earth-doped TiO2_{2}2​ thin films on III-V semiconductors for hybrid quantum photonic interfaces
Quantum photonic networks require two distinct functionalities: bright single-photon sources and long-lived quantum memories. III-V semiconductor quantum dots excel as deterministic and coherent photon emitters, while rare-earth ions such as erbium (Er3+^{3+}3+) in crystalline oxides offer exceptional spin and optical coherence at telecom wavelengths. Combining these systems and their functionalities via direct epitaxy is challenging due to lattice mismatch and incompatible growth conditions. Here we demonstrate low-temperature pulsed laser deposition of Er3+^{3+}3+-doped TiO2_{2}2​ thin films directly on GaAs and GaSb substrates. Controlled surface preparation with an arsenic cap and an oxygen-deficient buffer layer enables the growth of epitaxial anatase TiO2_{2}2​ (001) at 390o^{o}oC with sub-300 pm surface roughness, while avoiding interface degradation. In contrast, high-temperature oxide desorption or growth temperatures drive the transition to rough, polycrystalline rutile film, as confirmed by transmission electron microscopy. Minimal coincident interface area (MCIA) modeling explains the orientation-selective growth on GaAs and GaSb. Raman and cryogenic photoluminescence excitation spectroscopy verify the crystal phase and optical activation of Er3+^{3+}3+ ions. This multi-parameter growth strategy helps preserve III-V quantum dot functionality and yields smooth surfaces suitable for low-loss nanophotonic structures. Our results establish a materials platform for monolithically integrating rare-earth quantum memories with semiconductor photon sources, paving the way toward scalable hybrid quantum photonic chips.
Optical absorption and emission spectra are used to determine the energy levels of the 5I8^{5}I_{8}5I8​ ground state and 5I7^{5}I_{7}5I7​ excited state of Ho3+{\mathrm{Ho}}^{3+}Ho3+ in diamagnetic yttrium gallium garnet (YGaG) and ferrimagnetic yttrium iron garnet (YIG). The results for YGaG are consistent with the D2{D}_{2}D2​ site symmetry of the dodecahedral site in the garnet structure. Energy levels in YIG which are separated by site inequivalency are identified from spectra observed as the Fe3+{\mathrm{Fe}}^{3+}Fe3+ magnetization is rotated in the (11‾01\overline{1}0110) plane. Stimulated emission is observed from Ho3+{\mathrm{Ho}}^{3+}Ho3+ in YGaG at 2.086 and 2.114 \ensuremath{\mu} and from Ho3+{\mathrm{Ho}}^{3+}Ho3+ in YIG at 2.086, 2.089, and 2.107 \ensuremath{\mu}. Each of the lines in YIG is composed of two superimposed electronic transitions. The exchange field in YIG makes possible magnetic tuning of coherent emission over a range of 70 \AA{}.
Rare-earth ions (REIs) have incomplete 4f shells and possess narrow optical intra-4f transitions due to shielding from electrons in the 5s and 5p orbitals, making them good candidates for solid-state optical quantum memory. The emission of Er3+ in the telecom C-band (1530 nm–1565 nm) makes it especially attractive for this application. In order to build practical, scalable devices, the REI needs to be embedded in a non-interacting host material, preferably one that can be integrated with silicon. In this paper, we show that Er3+ can be isovalently incorporated into epitaxial Y2O3 thin films on Si (111). We report on the synthesis of epitaxial, single-crystalline Er:Y2O3 on Si with a narrow inhomogeneous linewidth in the photoluminescence (PL) spectra, 5.1 GHz (<100 mK), and an optical excited state lifetime of 8.1 ms. The choice of Y2O3 was driven by its low nuclear spin and small lattice mismatch with Si. Using PL and electron paramagnetic resonance, we show that Er3+ substitutes for Y in the crystal lattice. The role of interfacial SiOx, diffusion of silicon into the film, and the effect of buffer layers on the inhomogeneous PL linewidth are examined. We also find that the linewidth decreased monotonically with film thickness but surprisingly exhibits no correlation with the film crystalline quality, as measured by the x-ray rocking curve scans, suggesting other factors at play that limit the inhomogeneous broadening in Y2O3 films.