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

ACS Photonics

An Atomic Frequency Comb Memory in Rare-Earth-Doped Thin-Film Lithium Niobate

Subhojit Dutta, Yuqi Zhao, Uday Saha, Demitry Farfurnik, Elizabeth A. Goldschmidt, Edo Waks A

Published Mar 24, 2023• 25 citations
Publisher

Abstract

Quantum memories are a key building block for optical quantum computers and quantum networks. Rare-earth ion-doped crystals are a promising material to achieve quantum memory using an atomic frequency comb protocol. However, current atomic frequency comb memories typically use bulk materials or waveguides with large cross sections or rely on fabrication techniques not easily adaptable to wafer scale processing. Here, we demonstrate a compact chip-integrated atomic frequency comb in rare-earth-doped thin-film lithium niobate. Our optical memory exhibits a broad storage bandwidth exceeding 100 MHz and optical storage time as long as 250 ns. The enhanced optical confinement in this device leads to three orders of magnitude reduction in optical power required for a coherent control as compared to ion-diffused waveguides. These compact atomic frequency comb memories pave the way toward scalable, highly efficient, electro-optically tunable quantum photonic systems that can store and manipulate light on a compact chip.

DOI
10.1021/acsphotonics.2c01835

Related papers

An atomic frequency comb memory in rare-earth doped thin-film lithium niobate

Subhojit Dutta, Yuqi Zhao, Uday Saha +3 more

Atomic frequency combs memories that coherently store optical signals are a key building block for optical quantum computers and quantum networks. Integrating such memories into compact and chip-scale devices is essential for scalable quantum technology, but to date most demonstrations have been in bulk materials or waveguides with large cross-sections, or using fabrication techniques not easily adaptable to wafer scale processing. We demonstrate compact chip-integrated atomic frequency comb storage in rare earth doped thin-film lithium niobate. Our optical memory exhibits a broad storage bandwidth exceeding 100 MHz, and optical storage time of over 250 ns. The enhanced optical confinement in this device structure enables three orders of magnitude reduction in optical power as compared to large ion-diffused waveguides for the same Rabi frequency. These compact atomic frequency comb memories pave the way towards scalable, highly efficient, electro-optically tunable quantum photonic systems that can store and manipulate light on a compact chip.

arXiv:2111.01942•Nov 2, 2021•1 citation

An atomic frequency comb memory in rare-earth doped thin-film lithium niobate

Subhojit Dutta, Yuqi Zhao, Uday Saha +3 more

Abstract Atomic frequency combs memories that coherently store optical signals are a key building block for optical quantum computers1 and quantum networks2. Current atomic frequency combs typically use bulk materials or waveguides with large cross-sections3–5, or rely on fabrication techniques not easily adaptable to wafer scale processing6. Integrating such memories into compact and chip-scale devices is essential for scalable quantum technology. We demonstrate a compact chip-integrated atomic frequency comb in rare earth doped thin-film lithium niobate. Our optical memory exhibits a broad storage bandwidth exceeding 100 MHz, and optical storage time of over 250 ns. The enhanced optical confinement in this device leads to three orders of magnitude reduction in optical power required for coherent control as compared to ion-diffused waveguides 7. These compact atomic frequency comb memories pave the way towards scalable, highly efficient, electro-optically tunable quantum photonic systems that can store and manipulate light on a compact chip3.

•Apr 20, 2022•2 citations

An atomic frequency comb memory in rare-earth doped thin-film lithium niobate

Subhojit Dutta, Yuqi Zhao, Uday Saha +3 more

We demonstrate compact chip-integrated atomic frequency comb storage in rare-earth doped thin-film lithium niobate. Our optical memory exhibits a broad storage bandwidth exceeding 100 MHz, and optical storage time of over 250 ns.

Conference on Lasers and Electro-Optics•Jan 1, 2022•4 citations

Programmable cavity-enhanced telecom quantum memory in thin-film lithium niobate

Chengdong Yang, Hanwen Guo, Yu-Yang An +6 more

Spectrally multiplexed telecom quantum networks require quantum memories combining efficient storage with programmable frequency addressing. An integrated implementation should therefore unite a native telecom transition, efficient storage, and fast on-chip spectral control. Here we demonstrate a cavity-enhanced memory in an isotopically purified $^{167}\mathrm{Er}^{3+}$-doped thin-film lithium niobate microring. Long-lived hyperfine shelving states enable persistent, high-contrast atomic frequency comb preparation with a single-component lifetime of $277.6(52.6)$~s, while cavity impedance matching yields $23.3(5)\%$ on-chip efficiency for 100-ns storage. The intrinsic electro-optic response enables frequency-selective storage and routing at rates up to 20~MHz. We further store and retrieve time-energy-entangled telecom photons, violating an entanglement-witness bound by more than 11 standard deviations. Our results establish erbium-doped thin-film lithium niobate as a programmable light--matter interface for spectrally multiplexed quantum networks.

quant-pharXiv:2605.14777•May 15, 2026•1 citation

Integrated optical quantum memory controlled by the electro-optic effect

Xia-Xia Li, Pai Zhou, Yuhui Chen +1 more

Integrated optical quantum memories are a scalable solution to synchronize a large number of quantum nodes. Without compact quantum memories, some astonishing quantum applications such as distributed quantum computing and quantum sensor networks would not be possible. Rather than find a specific material that meets all the requirements of an on-chip quantum memory as other protocols usually do, we propose to assign the memory requirements on coherent storage and controllability to rare-earth ions and a lithium niobate crystal, respectively. Specifically, optical quantum states are stored in an erbium-doped lithium niobate microcavity by utilizing the electro-optic effect of lithium niobate. The cavity frequency can be shifted by an external electric field, thus modifying the resonance condition between the cavity and the collective atomic excitation. This effect is further used to suppress or enhance the emission of photon echoes. Our calculated results show that high efficiency and a low noise performance are achievable.

arXiv:2203.03887•Physical Review A•Jul 18, 2023•8 citations

Integrated Photonic Platform for Rare-Earth Ions in Thin Film Lithium Niobate

Subhojit Dutta, Elizabeth A. Goldschmidt, Sabyasachi Barik +2 more

Rare-earth ion ensembles doped in single crystals are a promising materials system with widespread applications in optical signal processing, lasing, and quantum information processing. Incorporating rare-earth ions into integrated photonic devices could enable compact lasers and modulators, as well as on-chip optical quantum memories for classical and quantum optical applications. To this end, a thin film single crystalline wafer structure that is compatible with planar fabrication of integrated photonic devices would be highly desirable. However, incorporating rare-earth ions into a thin film form-factor while preserving their optical properties has proven challenging. We demonstrate an integrated photonic platform for rare-earth ions doped in a single crystalline thin film lithium niobate on insulator. The thin film is composed of lithium niobate doped with Tm 3+ . The ions in the thin film exhibit optical lifetimes identical to those measured in bulk crystals. We show narrow spectral holes in a thin film waveguide that require up to 2 orders of magnitude lower power to generate than previously reported bulk waveguides. Our results pave the way for scalable on-chip lasers, optical signal processing devices, and integrated optical quantum memories.

arXiv:1911.06376•Nano Letters•Dec 19, 2019•99 citations
Quantum memories are a key building block for optical quantum computers and quantum networks. Rare-earth ion-doped crystals are a promising material to achieve quantum memory using an atomic frequency comb protocol. However, current atomic frequency comb memories typically use bulk materials or waveguides with large cross sections or rely on fabrication techniques not easily adaptable to wafer scale processing. Here, we demonstrate a compact chip-integrated atomic frequency comb in rare-earth-doped thin-film lithium niobate. Our optical memory exhibits a broad storage bandwidth exceeding 100 MHz and optical storage time as long as 250 ns. The enhanced optical confinement in this device leads to three orders of magnitude reduction in optical power required for a coherent control as compared to ion-diffused waveguides. These compact atomic frequency comb memories pave the way toward scalable, highly efficient, electro-optically tunable quantum photonic systems that can store and manipulate light on a compact chip.
Atomic frequency combs memories that coherently store optical signals are a key building block for optical quantum computers and quantum networks. Integrating such memories into compact and chip-scale devices is essential for scalable quantum technology, but to date most demonstrations have been in bulk materials or waveguides with large cross-sections, or using fabrication techniques not easily adaptable to wafer scale processing. We demonstrate compact chip-integrated atomic frequency comb storage in rare earth doped thin-film lithium niobate. Our optical memory exhibits a broad storage bandwidth exceeding 100 MHz, and optical storage time of over 250 ns. The enhanced optical confinement in this device structure enables three orders of magnitude reduction in optical power as compared to large ion-diffused waveguides for the same Rabi frequency. These compact atomic frequency comb memories pave the way towards scalable, highly efficient, electro-optically tunable quantum photonic systems that can store and manipulate light on a compact chip.
Abstract Atomic frequency combs memories that coherently store optical signals are a key building block for optical quantum computers1 and quantum networks2. Current atomic frequency combs typically use bulk materials or waveguides with large cross-sections3–5, or rely on fabrication techniques not easily adaptable to wafer scale processing6. Integrating such memories into compact and chip-scale devices is essential for scalable quantum technology. We demonstrate a compact chip-integrated atomic frequency comb in rare earth doped thin-film lithium niobate. Our optical memory exhibits a broad storage bandwidth exceeding 100 MHz, and optical storage time of over 250 ns. The enhanced optical confinement in this device leads to three orders of magnitude reduction in optical power required for coherent control as compared to ion-diffused waveguides 7. These compact atomic frequency comb memories pave the way towards scalable, highly efficient, electro-optically tunable quantum photonic systems that can store and manipulate light on a compact chip3.
Spectrally multiplexed telecom quantum networks require quantum memories combining efficient storage with programmable frequency addressing. An integrated implementation should therefore unite a native telecom transition, efficient storage, and fast on-chip spectral control. Here we demonstrate a cavity-enhanced memory in an isotopically purified 167Er3+^{167}\mathrm{Er}^{3+}167Er3+-doped thin-film lithium niobate microring. Long-lived hyperfine shelving states enable persistent, high-contrast atomic frequency comb preparation with a single-component lifetime of 277.6(52.6)277.6(52.6)277.6(52.6)~s, while cavity impedance matching yields 23.3(5)%23.3(5)\%23.3(5)% on-chip efficiency for 100-ns storage. The intrinsic electro-optic response enables frequency-selective storage and routing at rates up to 20~MHz. We further store and retrieve time-energy-entangled telecom photons, violating an entanglement-witness bound by more than 11 standard deviations. Our results establish erbium-doped thin-film lithium niobate as a programmable light--matter interface for spectrally multiplexed quantum networks.
Integrated optical quantum memories are a scalable solution to synchronize a large number of quantum nodes. Without compact quantum memories, some astonishing quantum applications such as distributed quantum computing and quantum sensor networks would not be possible. Rather than find a specific material that meets all the requirements of an on-chip quantum memory as other protocols usually do, we propose to assign the memory requirements on coherent storage and controllability to rare-earth ions and a lithium niobate crystal, respectively. Specifically, optical quantum states are stored in an erbium-doped lithium niobate microcavity by utilizing the electro-optic effect of lithium niobate. The cavity frequency can be shifted by an external electric field, thus modifying the resonance condition between the cavity and the collective atomic excitation. This effect is further used to suppress or enhance the emission of photon echoes. Our calculated results show that high efficiency and a low noise performance are achievable.
Rare-earth ion ensembles doped in single crystals are a promising materials system with widespread applications in optical signal processing, lasing, and quantum information processing. Incorporating rare-earth ions into integrated photonic devices could enable compact lasers and modulators, as well as on-chip optical quantum memories for classical and quantum optical applications. To this end, a thin film single crystalline wafer structure that is compatible with planar fabrication of integrated photonic devices would be highly desirable. However, incorporating rare-earth ions into a thin film form-factor while preserving their optical properties has proven challenging. We demonstrate an integrated photonic platform for rare-earth ions doped in a single crystalline thin film lithium niobate on insulator. The thin film is composed of lithium niobate doped with Tm 3+ . The ions in the thin film exhibit optical lifetimes identical to those measured in bulk crystals. We show narrow spectral holes in a thin film waveguide that require up to 2 orders of magnitude lower power to generate than previously reported bulk waveguides. Our results pave the way for scalable on-chip lasers, optical signal processing devices, and integrated optical quantum memories.