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:2206.12646

High cooperativity coupling of rare earth spins with planar superconducting resonator

Sihao Wang, Likai Yang, R. L. Cone, Charles W. Thiel, Hong Ming Tang

Published Jun 25, 2022• 0 citations
arXivHTMLPDF

Abstract

Interfacing superconducting microwave resonator with rare earth doped crystals presents a promising hybrid quantum system for applications including spin-assisted transducers and memories. The coupling strength between spins of rare earth ions and the microwave photons is characterized by the cooperativity. Here we report an ultra-high cooperativity $C \sim$ 650 between rare earth spins and a planar superconducting microwave resonator that features a highly uniform magnetic field for harnessing the strong anisotropic coupling strength of erbium doped yttrium orthosilicate. This cooperativity rivals that from a bulk dielectric resonator and paves a path for efficiently coupling of spins with microwave photons on an integrated platform.

DOI
10.48550/arxiv.2206.12646

Related papers

High-Cooperativity Coupling of Rare-Earth Spins to a Planar Superconducting Resonator

Sihao Wang, Likai Yang, R. L. Cone +2 more

In one branch of quantum information processing, high cooperativity between spins and a resonator is essential. Planar superconducting resonators present an opportunity for miniaturization and fully integrated circuitry, but unfortunately their cooperativity is a fraction of that of their bulk counterparts. This study designs a planar microwave resonator to achieve homogeneous magnetic field, and utilizes the anisotropic g-factor tensor of erbium spins in yttrium orthosilicate for maximum spin-photon coupling. Cooperativity on par with that of a three-dimensional cavity is achieved, marking an exciting step toward integrated circuits for spin quantum information processing.

Physical Review Applied•Jul 28, 2022•7 citations

High-Cooperativity Coupling of a Rare-Earth Spin Ensemble to a Superconducting Resonator Using Yttrium Orthosilicate as a Substrate

Gavin Dold, Zollitsch, CW, James O’Sullivan +6 more

Yttrium orthosilicate ( \nY \n2 \nSi \nO \n5 \n, or YSO) has proved to be a convenient host for rare-earth ions used in demonstrations of microwave quantum memories and optical memories with microwave interfaces and shows promise for coherent microwave-optical conversion owing to its favorable optical and spin properties. The strong coupling required by such microwave applications could be achieved using superconducting resonators patterned directly on \nY \n2 \nSi \nO \n5 \n and hence we investigate here the use of \nY \n2 \nSi \nO \n5 \n as an alternative to sapphire or silicon substrates for superconducting-hybrid-device fabrication. A \nNb \nN \n resonator with frequency 6.008 GHz and low-power quality factor \nQ \n≈ \n400 \n000 \n is fabricated on a \nY \n2 \nSi \nO \n5 \n substrate doped with isotopically enriched \n145 \nNd \n. Measurements of dielectric loss yield a loss tangent \ntan \n \nδ \n= \n4 \n× \n10 \n− \n6 \n, comparable to that of sapphire. Electron spin resonance (ESR) measurements performed using the resonator show the characteristic angular dependence expected from the anisotropic \n145 \nNd \n spin and the coupling strength between the resonator and the electron spins is in the high-cooperativity regime ( \nC \n= \n30 \n). These results demonstrate that \nY \n2 \nSi \nO \n5 \n is an excellent substrate for low-loss, high- \nQ \n microwave resonators, especially in applications for coupling to optically accessible rare-earth spins.

•May 29, 2019•19 citations

High-Cooperativity Coupling of a Rare-Earth Spin Ensemble to a Superconducting Resonator Using Yttrium Orthosilicate as a Substrate

Gavin Dold, Christoph W. Zollitsch, James O’Sullivan +6 more

Rare-earth ions (REIs) in solid hosts have important applications in the storage and conversion of quantum information at optical and microwave frequencies. Yttrium orthosilicate is a widely used host for REIs, with excellent optical properties, but its compatibility with superconducting resonators and circuits for quantum technology is not known. This study uses Y${}_{2}$SiO${}_{5}$ directly as a substrate for superconducting devices, revealing dielectric losses comparable to those of sapphire. This enables fabrication of high-quality microwave devices coupled to optically accessible rare-earth spins, pointing to applications in quantum storage and microwave-to-optical conversion.

arXiv:1901.03262•Physical Review Applied•May 29, 2019•25 citations

Coherent spin dynamics of rare-earth doped crystals in the high-cooperativity regime

Joseph Alexander, Gavin Dold, Oscar W. Kennedy +9 more

Rare-earth doped crystals have long coherence times and the potential to provide quantum interfaces between microwave and optical photons. Such applications benefit from a high cooperativity between the spin ensemble and a microwave cavity---this motivates an increase in the rare-earth ion concentration which in turn impacts the spin coherence lifetime. We measure spin dynamics of two rare-earth spin species, $^{145}\mathrm{Nd}$ and Yb, doped into ${\mathrm{Y}}_{\text{2}}{\mathrm{SiO}}_{\text{5}}$, coupled to a planar microwave resonator in the high-cooperativity regime, in the temperature range $1.2\phantom{\rule{0.16em}{0ex}}\mathrm{K}$ to $14\phantom{\rule{0.16em}{0ex}}\mathrm{mK}$. We identify relevant decoherence mechanisms, including instantaneous diffusion arising from resonant spins and temperature-dependent spectral diffusion from impurity electron and nuclear spins in the environment. We explore two methods to mitigate the effects of spectral diffusion in the Yb system in the low-temperature limit, first, using magnetic fields of up to 1 T to suppress impurity spin dynamics and, second, using transitions with low effective $g$ factors to reduce sensitivity to such dynamics. Finally, we demonstrate how the ``clock transition'' present in the $^{171}\mathrm{Yb}$ system at zero field can be used to increase coherence times up to ${T}_{2}=6(1)\phantom{\rule{0.16em}{0ex}}\mathrm{ms}$.

arXiv:2206.04027•Physical review. B./Physical review. B•Dec 14, 2022•21 citations

Hybrid microring resonator devices for rare-earth quantum-light matter interfaces (Conference Presentation)

Ioana Craiciu, Evan Miyazono, Tian Zhong +2 more

Rare earth quantum light-matter interfaces (QLMIs) are uniquely suited for various quantum communication applications, including quantum memories and quantum optical to microwave transducers. Among rare earths, erbium QLMIs are particularly appealing due to erbium’s long lived telecom wavelength resonance, allowing integration with existing optical communication technology and infrastructure. Micro-resonator QLMIs have various advantages over bulk rare earth crystal memories. They provide the opportunity for on-chip integration; for example, optical resonators can be integrated with microwave resonators for quantum optical-microwave transduction. For spectral hole-burning based quantum memories, coupling rare earth ions to a resonator can provide improved memory initialization via Purcell enhancement of optical lifetimes, while impedance matching the resonator to the ions can raise the theoretical memory efficiency to 100%. We present hybrid nanoscale quantum light matter interfaces in the form of amorphous silicon ring resonators on yttrium orthosilicate (YSO) substrate doped with erbium ions. While working with rare earth crystal hosts can be challenging, the fabrication process for these devices is simple and robust, using traditional thin film fabrication technologies. Our devices have measured quality factors of over 105 in the 11 µm diameter rings, and evanescent coupling to an ensemble of erbium ions characterized by a cooperativity of 0.54. We present simulation and experimental results of the optical properties of these cavities, and their coupling to erbium ions, including a demonstration of Purcell enhancement of the erbium telecom transition. We then analyze their potential as quantum memories and in optical to microwave transducers.

•Apr 28, 2017•0 citations

Hybrid microring resonator devices for rare-earth quantum-light matter interfaces

Ioana Craiciu, Evan Miyazono, Tian Zhong +2 more

Rare earth quantum light-matter interfaces (QLMIs) are uniquely suited for various quantum communication applications, including quantum memories and quantum optical to microwave transducers. Among rare earths, erbium QLMIs are particularly appealing due to erbium’s long lived telecom wavelength resonance, allowing integration with existing optical communication technology and infrastructure. Micro-resonator QLMIs have various advantages over bulk rare earth crystal memories. They provide the opportunity for on-chip integration; for example, optical resonators can be integrated with microwave resonators for quantum optical-microwave transduction. For spectral hole-burning based quantum memories, coupling rare earth ions to a resonator can provide improved memory initialization via Purcell enhancement of optical lifetimes, while impedance matching the resonator to the ions can raise the theoretical memory efficiency to 100%. We present hybrid nanoscale quantum light matter interfaces in the form of amorphous silicon ring resonators on yttrium orthosilicate (YSO) substrate doped with erbium ions. While working with rare earth crystal hosts can be challenging, the fabrication process for these devices is simple and robust, using traditional thin film fabrication technologies. Our devices have measured quality factors of over 105 in the 11 µm diameter rings, and evanescent coupling to an ensemble of erbium ions characterized by a cooperativity of 0.54. We present simulation and experimental results of the optical properties of these cavities, and their coupling to erbium ions, including a demonstration of Purcell enhancement of the erbium telecom transition. We then analyze their potential as quantum memories and in optical to microwave transducers.

•Jun 2, 2017•0 citations
Interfacing superconducting microwave resonator with rare earth doped crystals presents a promising hybrid quantum system for applications including spin-assisted transducers and memories. The coupling strength between spins of rare earth ions and the microwave photons is characterized by the cooperativity. Here we report an ultra-high cooperativity C∼C \simC∼ 650 between rare earth spins and a planar superconducting microwave resonator that features a highly uniform magnetic field for harnessing the strong anisotropic coupling strength of erbium doped yttrium orthosilicate. This cooperativity rivals that from a bulk dielectric resonator and paves a path for efficiently coupling of spins with microwave photons on an integrated platform.
In one branch of quantum information processing, high cooperativity between spins and a resonator is essential. Planar superconducting resonators present an opportunity for miniaturization and fully integrated circuitry, but unfortunately their cooperativity is a fraction of that of their bulk counterparts. This study designs a planar microwave resonator to achieve homogeneous magnetic field, and utilizes the anisotropic g-factor tensor of erbium spins in yttrium orthosilicate for maximum spin-photon coupling. Cooperativity on par with that of a three-dimensional cavity is achieved, marking an exciting step toward integrated circuits for spin quantum information processing.
Yttrium orthosilicate ( \nY \n2 \nSi \nO \n5 \n, or YSO) has proved to be a convenient host for rare-earth ions used in demonstrations of microwave quantum memories and optical memories with microwave interfaces and shows promise for coherent microwave-optical conversion owing to its favorable optical and spin properties. The strong coupling required by such microwave applications could be achieved using superconducting resonators patterned directly on \nY \n2 \nSi \nO \n5 \n and hence we investigate here the use of \nY \n2 \nSi \nO \n5 \n as an alternative to sapphire or silicon substrates for superconducting-hybrid-device fabrication. A \nNb \nN \n resonator with frequency 6.008 GHz and low-power quality factor \nQ \n≈ \n400 \n000 \n is fabricated on a \nY \n2 \nSi \nO \n5 \n substrate doped with isotopically enriched \n145 \nNd \n. Measurements of dielectric loss yield a loss tangent \ntan \n \nδ \n= \n4 \n× \n10 \n− \n6 \n, comparable to that of sapphire. Electron spin resonance (ESR) measurements performed using the resonator show the characteristic angular dependence expected from the anisotropic \n145 \nNd \n spin and the coupling strength between the resonator and the electron spins is in the high-cooperativity regime ( \nC \n= \n30 \n). These results demonstrate that \nY \n2 \nSi \nO \n5 \n is an excellent substrate for low-loss, high- \nQ \n microwave resonators, especially in applications for coupling to optically accessible rare-earth spins.
Rare-earth ions (REIs) in solid hosts have important applications in the storage and conversion of quantum information at optical and microwave frequencies. Yttrium orthosilicate is a widely used host for REIs, with excellent optical properties, but its compatibility with superconducting resonators and circuits for quantum technology is not known. This study uses Y2{}_{2}2​SiO5{}_{5}5​ directly as a substrate for superconducting devices, revealing dielectric losses comparable to those of sapphire. This enables fabrication of high-quality microwave devices coupled to optically accessible rare-earth spins, pointing to applications in quantum storage and microwave-to-optical conversion.
Rare-earth doped crystals have long coherence times and the potential to provide quantum interfaces between microwave and optical photons. Such applications benefit from a high cooperativity between the spin ensemble and a microwave cavity---this motivates an increase in the rare-earth ion concentration which in turn impacts the spin coherence lifetime. We measure spin dynamics of two rare-earth spin species, 145Nd^{145}\mathrm{Nd}145Nd and Yb, doped into Y2SiO5{\mathrm{Y}}_{\text{2}}{\mathrm{SiO}}_{\text{5}}Y2​SiO5​, coupled to a planar microwave resonator in the high-cooperativity regime, in the temperature range 1.2K1.2\phantom{\rule{0.16em}{0ex}}\mathrm{K}1.2K to 14mK14\phantom{\rule{0.16em}{0ex}}\mathrm{mK}14mK. We identify relevant decoherence mechanisms, including instantaneous diffusion arising from resonant spins and temperature-dependent spectral diffusion from impurity electron and nuclear spins in the environment. We explore two methods to mitigate the effects of spectral diffusion in the Yb system in the low-temperature limit, first, using magnetic fields of up to 1 T to suppress impurity spin dynamics and, second, using transitions with low effective ggg factors to reduce sensitivity to such dynamics. Finally, we demonstrate how the ``clock transition'' present in the 171Yb^{171}\mathrm{Yb}171Yb system at zero field can be used to increase coherence times up to T2=6(1)ms{T}_{2}=6(1)\phantom{\rule{0.16em}{0ex}}\mathrm{ms}T2​=6(1)ms.
Rare earth quantum light-matter interfaces (QLMIs) are uniquely suited for various quantum communication applications, including quantum memories and quantum optical to microwave transducers. Among rare earths, erbium QLMIs are particularly appealing due to erbium’s long lived telecom wavelength resonance, allowing integration with existing optical communication technology and infrastructure. Micro-resonator QLMIs have various advantages over bulk rare earth crystal memories. They provide the opportunity for on-chip integration; for example, optical resonators can be integrated with microwave resonators for quantum optical-microwave transduction. For spectral hole-burning based quantum memories, coupling rare earth ions to a resonator can provide improved memory initialization via Purcell enhancement of optical lifetimes, while impedance matching the resonator to the ions can raise the theoretical memory efficiency to 100%. We present hybrid nanoscale quantum light matter interfaces in the form of amorphous silicon ring resonators on yttrium orthosilicate (YSO) substrate doped with erbium ions. While working with rare earth crystal hosts can be challenging, the fabrication process for these devices is simple and robust, using traditional thin film fabrication technologies. Our devices have measured quality factors of over 105 in the 11 µm diameter rings, and evanescent coupling to an ensemble of erbium ions characterized by a cooperativity of 0.54. We present simulation and experimental results of the optical properties of these cavities, and their coupling to erbium ions, including a demonstration of Purcell enhancement of the erbium telecom transition. We then analyze their potential as quantum memories and in optical to microwave transducers.
Rare earth quantum light-matter interfaces (QLMIs) are uniquely suited for various quantum communication applications, including quantum memories and quantum optical to microwave transducers. Among rare earths, erbium QLMIs are particularly appealing due to erbium’s long lived telecom wavelength resonance, allowing integration with existing optical communication technology and infrastructure. Micro-resonator QLMIs have various advantages over bulk rare earth crystal memories. They provide the opportunity for on-chip integration; for example, optical resonators can be integrated with microwave resonators for quantum optical-microwave transduction. For spectral hole-burning based quantum memories, coupling rare earth ions to a resonator can provide improved memory initialization via Purcell enhancement of optical lifetimes, while impedance matching the resonator to the ions can raise the theoretical memory efficiency to 100%. We present hybrid nanoscale quantum light matter interfaces in the form of amorphous silicon ring resonators on yttrium orthosilicate (YSO) substrate doped with erbium ions. While working with rare earth crystal hosts can be challenging, the fabrication process for these devices is simple and robust, using traditional thin film fabrication technologies. Our devices have measured quality factors of over 105 in the 11 µm diameter rings, and evanescent coupling to an ensemble of erbium ions characterized by a cooperativity of 0.54. We present simulation and experimental results of the optical properties of these cavities, and their coupling to erbium ions, including a demonstration of Purcell enhancement of the erbium telecom transition. We then analyze their potential as quantum memories and in optical to microwave transducers.