© 2026 Aqora Quantum S.A.S.

Terms Privacy Legal Notice

arXiv:2511.05740 · Physical Review Applied

Quantum Nanophotonic Interface for Tin-Vacancy Centers in Thin-Film Diamond

Hope Lee, Hannah C. Kleidermacher, Abigail J. M. Stein, Hyunseok Oh, Lillian B. Hughes Wyatt, Casey K. Kim, Luca Basso, Andrew M. Mounce, Yongqiang Wang, Shei S. Su, Michael Titze, Ania C. Bleszynski Jayich, Jelena Vučković

quant-phphysics.opticsSubmitted Nov 7, 2025• Announced Nov 11, 2025• 0 citations

v1 · Nov 7, 2025 v2 · Mar 13, 2026

Abstract

The negatively charged tin-vacancy center in diamond (SnV-) is an excellent solid state qubit with optically-addressable transitions and a long electron spin coherence time at elevated temperatures. However, implementing scalable quantum nodes with high-fidelity optical readout of the electron spin state requires efficient photon emission and collection from the system. In this manuscript, we report a quantum photonic interface for SnV- centers based on one-dimensional photonic crystal cavities fabricated in diamond thin films. Furthermore, we develop a model describing the spontaneous emission dynamics of our system, allowing for rigorous determination of Purcell factors and the C/D branching ratio from cavity enhancement of the C and D transitions of the SnV- zero phonon line. We observe quality factors up to ~6000 across this sample, and measure up to a 12-fold lifetime reduction. By considering the lifetime reduction of both the C and D transitions independently, we determine the C/D branching ratio to be ηBR=0.7815, in line with previous theoretical and experimental findings. Finally from our analysis, we extract a Purcell factor of up to Fc=26.21(0.01) for a single SnV- transition.

Comments: 15 total pages, 3 figures, 11 supplemental figures

Related papers

Quantum Photonic Interface for Tin-Vacancy Centers in Diamond

Alison E. Rugar, Shahriar Aghaeimeibodi, Daniel Riedel +6 more

The realization of quantum networks critically depends on establishing efficient, coherent light-matter interfaces. Optically active spins in diamond have emerged as promising quantum nodes based on their spin-selective optical transitions, long-lived spin ground states, and potential for integration with nanophotonics. Tin-vacancy (SnV$^{\,\textrm{-}}$) centers in diamond are of particular interest because they exhibit narrow-linewidth emission in nanostructures and possess long spin coherence times at temperatures above 1 K. However, a nanophotonic interface for SnV$^{\,\textrm{-}}$ centers has not yet been realized. Here, we report cavity enhancement of the emission of SnV$^{\,\textrm{-}}$ centers in diamond. We integrate SnV$^{\,\textrm{-}}$ centers into one-dimensional photonic crystal resonators and observe a 40-fold increase in emission intensity. The Purcell factor of the coupled system is 25, resulting in channeling of the majority of photons ($90\%$) into the cavity mode. Our results pave the way for the creation of efficient, scalable spin-photon interfaces based on SnV$^{\,\textrm{-}}$ centers in diamond.

arXiv:2102.11852•Physical Review X•Jul 26, 2021•103 citations

Purcell Enhancement of Tin-Vacancy Centers in Thin-Film Diamond Cavities

Hannah Calzi Kleidermacher, Hope Lee, Abigail Stein +10 more

We couple tin-vacancy (SnV − ) centers in thin-film diamond to one-dimensional photonic crystal cavities of different orientations and develop a spontaneous emission model that rigorously quantifies Purcell factors and the branching ratio of the zero-phonon line (ZPL) transitions.

•Jan 1, 2026•0 citations

A nanophotonic interface for tin-vacancy spin qubits in diamond

Shahriar Aghaeimeibodi, Alison E. Rugar, Daniel Riedel +8 more

Building quantum networks requires efficient coupling of solid-state quantum emitters to photonic devices. Tinvacancy center (SnV) has attracted much interest for having long spin coherence times at temperatures above 1 K. Employing SnV as an optically addressable qubit requires integration with photonic structures to both route the emitted photons and enhance the light-matter interaction. We present incorporation of high-quality SnV centers with narrow linewidths in suspended diamond waveguides. Furthermore, we fabricate photonic crystal cavities in diamond with embedded SnV centers. We observe strong intensity enhancement of the photon emission when the cavity is resonant with the color center. Time-resolved photoluminescence measurements confirm that this effect is due to radiative Purcell enhancement of the spontaneous emission. Finally, we demonstrate Stark tuning of transition frequency of SnV centers, essential for multiemitter applications. These results are a significant step toward color-center-based quantum information processing applications without the need for dilution refrigerators.

Quantum Nanophotonic Materials, Devices, and Systems•Jul 30, 2021•1 citation

Coupling of a single tin-vacancy center to a photonic crystal cavity in diamond

Kazuhiro Kuruma, Benjamin Pingault, Cleaven Chia +5 more

We demonstrate optical coupling between a single tin-vacancy (SnV) center in diamond and a free-standing photonic crystal nanobeam cavity. The cavities are fabricated using quasi-isotropic etching and feature experimentally measured quality factors as high as ∼11 000. We investigate the dependence of a single SnV center's emission by controlling the cavity wavelength using a laser-induced gas desorption technique. Under resonance conditions, we observe an intensity enhancement of the SnV emission by a factor of 12 and a 16-fold reduction of the SnV lifetime. Based on the large enhancement of the SnV emission rate inside the cavity, we estimate the Purcell factor for the SnV zero-phonon line to be 37 and the coupling efficiency of the SnV center to the cavity, the β factor, to be 95%. Our work paves the way for the realization of quantum photonic devices and systems based on efficient photonic interfaces using the SnV color center in diamond.

arXiv:2105.01715•Applied Physics Letters•Jun 7, 2021•78 citations

Above-Unity Coherent Cooperativity of Tin-Vacancy Centers in Diamond Photonic Crystal Cavities

Nina Codreanu, Tim Turan, Daniel Bedialauneta Rodriguez +8 more

The tin-vacancy center in diamond (SnV) has emerged as a compelling building block for realizing next-generation quantum networks thanks to its excellent optical and spin properties. Coupling to photonic crystal cavities (PCCs) promises to further enhance the SnV light-matter interface and unlock a diverse range of entanglement generation protocols. Recent pioneering experiments showing Purcell enhancement of SnV centers in PCCs underscore this potential. However, optical coupling that is coherent - the key ingredient for use in quantum protocols - has so far remained elusive. Here, we demonstrate above-unity coherent cooperativity of SnV centers embedded in photonic crystal cavities. We fabricate free-standing PCCs using a quasi-isotropic undercut. Across two samples, we conduct room-temperature characterizations, measuring resonances for 327 cavities, with an average quality factor exceeding $Q = 1.0(3) \times 10^4$. Two cavity-coupled emitters are examined in detail, exhibiting quality factors up to $Q = 25.4(4) \times 10^3$ and Purcell-reduced lifetimes corresponding to cooperativities up to $C = 20.6(11)$. Furthermore, the single SnVs are observed to strongly modulate the cavity transmission with an extinction contrast up to $98.8(4) \%$ on resonance. Finally, SnV linewidth measurements reveal above-unity coherent cooperativities in both devices, with the highest value being $C_\mathrm{coh} = 8.3(12)$. These results open the door to using cavity-coupled SnV centers as efficient, coherent light-matter interfaces for future quantum networks.

quant-pharXiv:2511.13375•Physical Review X•Nov 18, 2025•4 citations

Purcell enhancement of tin-vacancy centers in diamond

Daniel Riedel, Alison E. Rugar, Shahriar Aghaeimeibodi +6 more

Quantum networks rely on the efficient coupling of coherent quantum memories to photonic links. Tin-vacancy centers (SnV) have emerged as promising candidates for the implementation of an optically interfaced quantum memory based on their long spin coherence times at temperatures above 1K. To enhance their interaction with photons SnV centers need to be integrated with high-quality photonic structures. In this work, we report the enhancement of coherent emission of SnV centers by coupling them to a nanophotonic waveguide resonator. We observe strong intensity enhancement of the photon emission when the cavity is resonant with the color center. We demonstrate strong enhancement of the radiative recombination rate of SnV centers resulting in their predominant emission via the coherent zero-phonon line and into the cavity mode. These results are a significant step toward color-center-based quantum information processing applications without the need for dilution refrigerators.

Quantum Computing, Communication, and Simulation•Mar 9, 2022•0 citations

The negatively charged tin-vacancy center in diamond (SnV-) is an excellent solid state qubit with optically-addressable transitions and a long electron spin coherence time at elevated temperatures. However, implementing scalable quantum nodes with high-fidelity optical readout of the electron spin state requires efficient photon emission and collection from the system. In this manuscript, we report a quantum photonic interface for SnV- centers based on one-dimensional photonic crystal cavities fabricated in diamond thin films. Furthermore, we develop a model describing the spontaneous emission dynamics of our system, allowing for rigorous determination of Purcell factors and the C/D branching ratio from cavity enhancement of the C and D transitions of the SnV- zero phonon line. We observe quality factors up to ~6000 across this sample, and measure up to a 12-fold lifetime reduction. By considering the lifetime reduction of both the C and D transitions independently, we determine the C/D branching ratio to be ηBR=0.7815, in line with previous theoretical and experimental findings. Finally from our analysis, we extract a Purcell factor of up to Fc=26.21(0.01) for a single SnV- transition.

The realization of quantum networks critically depends on establishing efficient, coherent light-matter interfaces. Optically active spins in diamond have emerged as promising quantum nodes based on their spin-selective optical transitions, long-lived spin ground states, and potential for integration with nanophotonics. Tin-vacancy (SnV

^{\,\textrm{-}}

) centers in diamond are of particular interest because they exhibit narrow-linewidth emission in nanostructures and possess long spin coherence times at temperatures above 1 K. However, a nanophotonic interface for SnV

^{\,\textrm{-}}

centers has not yet been realized. Here, we report cavity enhancement of the emission of SnV

^{\,\textrm{-}}

centers in diamond. We integrate SnV

^{\,\textrm{-}}

centers into one-dimensional photonic crystal resonators and observe a 40-fold increase in emission intensity. The Purcell factor of the coupled system is 25, resulting in channeling of the majority of photons (

90\%

) into the cavity mode. Our results pave the way for the creation of efficient, scalable spin-photon interfaces based on SnV

^{\,\textrm{-}}

centers in diamond.

Building quantum networks requires efficient coupling of solid-state quantum emitters to photonic devices. Tinvacancy center (SnV) has attracted much interest for having long spin coherence times at temperatures above 1 K. Employing SnV as an optically addressable qubit requires integration with photonic structures to both route the emitted photons and enhance the light-matter interaction. We present incorporation of high-quality SnV centers with narrow linewidths in suspended diamond waveguides. Furthermore, we fabricate photonic crystal cavities in diamond with embedded SnV centers. We observe strong intensity enhancement of the photon emission when the cavity is resonant with the color center. Time-resolved photoluminescence measurements confirm that this effect is due to radiative Purcell enhancement of the spontaneous emission. Finally, we demonstrate Stark tuning of transition frequency of SnV centers, essential for multiemitter applications. These results are a significant step toward color-center-based quantum information processing applications without the need for dilution refrigerators.

We demonstrate optical coupling between a single tin-vacancy (SnV) center in diamond and a free-standing photonic crystal nanobeam cavity. The cavities are fabricated using quasi-isotropic etching and feature experimentally measured quality factors as high as ∼11 000. We investigate the dependence of a single SnV center's emission by controlling the cavity wavelength using a laser-induced gas desorption technique. Under resonance conditions, we observe an intensity enhancement of the SnV emission by a factor of 12 and a 16-fold reduction of the SnV lifetime. Based on the large enhancement of the SnV emission rate inside the cavity, we estimate the Purcell factor for the SnV zero-phonon line to be 37 and the coupling efficiency of the SnV center to the cavity, the β factor, to be 95%. Our work paves the way for the realization of quantum photonic devices and systems based on efficient photonic interfaces using the SnV color center in diamond.

The tin-vacancy center in diamond (SnV) has emerged as a compelling building block for realizing next-generation quantum networks thanks to its excellent optical and spin properties. Coupling to photonic crystal cavities (PCCs) promises to further enhance the SnV light-matter interface and unlock a diverse range of entanglement generation protocols. Recent pioneering experiments showing Purcell enhancement of SnV centers in PCCs underscore this potential. However, optical coupling that is coherent - the key ingredient for use in quantum protocols - has so far remained elusive. Here, we demonstrate above-unity coherent cooperativity of SnV centers embedded in photonic crystal cavities. We fabricate free-standing PCCs using a quasi-isotropic undercut. Across two samples, we conduct room-temperature characterizations, measuring resonances for 327 cavities, with an average quality factor exceeding

Q = 1.0(3) \times 10^4

. Two cavity-coupled emitters are examined in detail, exhibiting quality factors up to

Q = 25.4(4) \times 10^3

and Purcell-reduced lifetimes corresponding to cooperativities up to

C = 20.6(11)

. Furthermore, the single SnVs are observed to strongly modulate the cavity transmission with an extinction contrast up to

98.8(4) \%

on resonance. Finally, SnV linewidth measurements reveal above-unity coherent cooperativities in both devices, with the highest value being

C_\mathrm{coh} = 8.3(12)

. These results open the door to using cavity-coupled SnV centers as efficient, coherent light-matter interfaces for future quantum networks.

Quantum networks rely on the efficient coupling of coherent quantum memories to photonic links. Tin-vacancy centers (SnV) have emerged as promising candidates for the implementation of an optically interfaced quantum memory based on their long spin coherence times at temperatures above 1K. To enhance their interaction with photons SnV centers need to be integrated with high-quality photonic structures. In this work, we report the enhancement of coherent emission of SnV centers by coupling them to a nanophotonic waveguide resonator. We observe strong intensity enhancement of the photon emission when the cavity is resonant with the color center. We demonstrate strong enhancement of the radiative recombination rate of SnV centers resulting in their predominant emission via the coherent zero-phonon line and into the cavity mode. These results are a significant step toward color-center-based quantum information processing applications without the need for dilution refrigerators.