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:2510.26870 · Physical Review Research

Single-photon-level atomic frequency comb storage in room temperature alkali vapor

Zakary Schofield, V. Laurindo, Ori Ezrah Mor, Patrick M. Ledingham

Published Jan 29, 2026• 0 citations
arXivHTMLPDF

Abstract

We have demonstrated the coherent storage and retrieval of single-photon-level light using the atomic frequency comb protocol in a room temperature rubidium vapor. Velocity-selective optical pumping is used to prepare the comb within the F = 2 hyperfine ground state of rubidium, with the spacing between peaks coinciding with half the F = 2 − F = 3 hyperfine splitting of the 5 P 3 / 2 2 excited state. Weak coherent states of average photon number μ in = 0.083 ( 5 ) are stored with preprogrammed recall time of 7.5 ns with an efficiency of η AFC = 6.59 ( 5 ) % , while two temporally distinct modes have been stored and recalled with η AFC = 2.6 ( 1 ) % , allowing for time-bin qubit storage. Finally, the storage efficiency is observed to be independent of the input pulse polarization, satisfying a necessary condition for polarization qubit storage.

DOI
10.1103/y4kq-ckhq

Related papers

Room temperature atomic frequency comb storage for light

D. Main, T. M. Hird, Shaobo Gao +2 more

We demonstrate coherent storage and retrieval of pulsed light using the atomic frequency comb protocol in a room temperature alkali vapor. We utilize velocity-selective optical pumping to prepare multiple velocity classes in the F = 4 hyperfine ground state of cesium. The frequency spacing of the classes is chosen to coincide with the F ′ = 4 − F ′ = 5 hyperfine splitting of the 6 2 P 3 / 2 excited state, resulting in a broadband periodic absorbing structure consisting of two usually Doppler-broadened optical transitions. Weak coherent states of duration 2 n s are mapped into this atomic frequency comb with pre-programmed recall times of 8 n s and 12 n s , with multi-temporal mode storage and recall demonstrated. Utilizing two transitions in the comb leads to an additional interference effect upon rephasing that enhances the recall efficiency.

arXiv:2011.03765•Optics Letters•May 18, 2021•15 citations

Efficient cavity-assisted storage of photonic qubits in a solid-state quantum memory

Stefano Duranti, Sören Wengerowsky, Leo Feldmann +3 more

We report on the high-efficiency storage and retrieval of weak coherent optical pulses and photonic qubits in a cavity-enhanced solid-state quantum memory. By using an atomic frequency comb (AFC) memory in a Pr 3+ :Y 2 SiO 5 crystal embedded in an impedance-matched cavity, we stored weak coherent pulses at the single photon level with up to 62% efficiency for a pre-determined storage time of 2 µs. We also confirmed that the impedance-matched cavity enhances the efficiency for longer storage times up to 70 µs. Harnessing the temporal multimodality of the AFC scheme, we stored weak coherent time-bin qubits with a record (51 ± 2%) efficiency and a fidelity over (94.8 ± 1.4)%, limited by imperfections in the qubits creation and measurement.

arXiv:2307.03509•Optics Express•Jul 8, 2024•30 citations

Coherent storage of temporally multimode light using a spin-wave atomic frequency comb memory

Mustafa Gündoğan, Margherita Mazzera, Patrick M. Ledingham +2 more

We report on the coherent and multi-temporal mode storage of light using the full atomic frequency comb memory scheme. The scheme involves the transfer of optical atomic excitations in Pr 3+ :Y 2 SiO 5 to spin waves in hyperfine levels using strong single-frequency transfer pulses. Using this scheme, a total of five temporal modes are stored and recalled on-demand from the memory. The coherence of the storage and retrieval is characterized using a time-bin interference measurement resulting in visibilities higher than 80%, independent of the storage time. This coherent and multimode spin-wave memory is promising as a quantum memory for light.

arXiv:1301.3048•New Journal of Physics•Apr 19, 2013•75 citations

Single-photon-level optical storage in a solid-state spin-wave memory

Nuala Timoney, Imam Usmani, Pierre Jobez +2 more

A long-lived quantum memory is a firm requirement for implementing a quantum repeater scheme. Recent progress in solid-state rare-earth-ion-doped systems justifies their status as very strong candidates for such systems. Nonetheless an optical memory based on spin-wave storage at the single-photon level has not been shown in such a system to date, which is crucial for achieving the long storage times required for quantum repeaters. In this paper we show that it is possible to execute a complete atomic frequency comb (AFC) scheme, including spin-wave storage, with weak coherent pulses of $\overline{n}=2.5\ifmmode\pm\else\textpm\fi{}0.6$ photons per pulse. We discuss in detail the experimental steps required to obtain this result and demonstrate the coherence of a stored time-bin pulse. We show a noise level of $(7.1\ifmmode\pm\else\textpm\fi{}2.3)\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}3}$ photons per mode during storage, and this relatively low noise level paves the way for future quantum optics experiments using spin waves in rare-earth-doped crystals.

arXiv:1301.6924•Physical Review A•Aug 20, 2013•72 citations

Preparing narrow velocity distributions for quantum memories in room-temperature alkali-metal vapors

D. Main, T. M. Hird, Shaobo Gao +4 more

Quantum memories are a crucial technology for enabling large-scale quantum networks through synchronization of probabilistic operations. Such networks impose strict requirements on quantum memory, such as storage time, retrieval efficiency, bandwidth, and scalability. On- and off-resonant ladder protocols on warm atomic vapor platforms are promising candidates, combining efficient high-bandwidth operation with low-noise on-demand retrieval. However, their storage time is severely limited by motion-induced dephasing caused by the broad velocity distribution of atoms composing the vapor. In this paper, we demonstrate velocity selective optical pumping to overcome this decoherence mechanism. This will increase the achievable memory storage time of vapor memories. This technique can also be used for preparing arbitrarily shaped absorption profiles, for instance, preparing an atomic frequency comb absorption feature.

arXiv:2011.03766•Physical Review A•Apr 12, 2021•18 citations

Room-Temperature Single-photon level Memory for Polarization States

Connor Kupchak, Thomas Mittiga, Bertus Jordaan +3 more

An optical quantum memory is a stationary device that is capable of storing and recreating photonic qubits with a higher fidelity than any classical device. Thus far, these two requirements have been fulfilled for polarization qubits in systems based on cold atoms and cryogenically cooled crystals. Here, we report a room-temperature memory capable of storing arbitrary polarization qubits with a signal-to-background ratio higher than 1 and an average fidelity surpassing the classical benchmark for weak laser pulses containing 1.6 photons on average, without taking into account non-unitary operation. Our results demonstrate that a common vapor cell can reach the low background noise levels necessary for polarization qubit storage using single-photon level light, and propels atomic-vapor systems towards a level of functionality akin to other quantum information processing architectures.

Scientific Reports•Jan 7, 2015•35 citations
We have demonstrated the coherent storage and retrieval of single-photon-level light using the atomic frequency comb protocol in a room temperature rubidium vapor. Velocity-selective optical pumping is used to prepare the comb within the F = 2 hyperfine ground state of rubidium, with the spacing between peaks coinciding with half the F = 2 − F = 3 hyperfine splitting of the 5 P 3 / 2 2 excited state. Weak coherent states of average photon number μ in = 0.083 ( 5 ) are stored with preprogrammed recall time of 7.5 ns with an efficiency of η AFC = 6.59 ( 5 ) % , while two temporally distinct modes have been stored and recalled with η AFC = 2.6 ( 1 ) % , allowing for time-bin qubit storage. Finally, the storage efficiency is observed to be independent of the input pulse polarization, satisfying a necessary condition for polarization qubit storage.
We demonstrate coherent storage and retrieval of pulsed light using the atomic frequency comb protocol in a room temperature alkali vapor. We utilize velocity-selective optical pumping to prepare multiple velocity classes in the F = 4 hyperfine ground state of cesium. The frequency spacing of the classes is chosen to coincide with the F ′ = 4 − F ′ = 5 hyperfine splitting of the 6 2 P 3 / 2 excited state, resulting in a broadband periodic absorbing structure consisting of two usually Doppler-broadened optical transitions. Weak coherent states of duration 2 n s are mapped into this atomic frequency comb with pre-programmed recall times of 8 n s and 12 n s , with multi-temporal mode storage and recall demonstrated. Utilizing two transitions in the comb leads to an additional interference effect upon rephasing that enhances the recall efficiency.
We report on the high-efficiency storage and retrieval of weak coherent optical pulses and photonic qubits in a cavity-enhanced solid-state quantum memory. By using an atomic frequency comb (AFC) memory in a Pr 3+ :Y 2 SiO 5 crystal embedded in an impedance-matched cavity, we stored weak coherent pulses at the single photon level with up to 62% efficiency for a pre-determined storage time of 2 µs. We also confirmed that the impedance-matched cavity enhances the efficiency for longer storage times up to 70 µs. Harnessing the temporal multimodality of the AFC scheme, we stored weak coherent time-bin qubits with a record (51 ± 2%) efficiency and a fidelity over (94.8 ± 1.4)%, limited by imperfections in the qubits creation and measurement.
We report on the coherent and multi-temporal mode storage of light using the full atomic frequency comb memory scheme. The scheme involves the transfer of optical atomic excitations in Pr 3+ :Y 2 SiO 5 to spin waves in hyperfine levels using strong single-frequency transfer pulses. Using this scheme, a total of five temporal modes are stored and recalled on-demand from the memory. The coherence of the storage and retrieval is characterized using a time-bin interference measurement resulting in visibilities higher than 80%, independent of the storage time. This coherent and multimode spin-wave memory is promising as a quantum memory for light.
A long-lived quantum memory is a firm requirement for implementing a quantum repeater scheme. Recent progress in solid-state rare-earth-ion-doped systems justifies their status as very strong candidates for such systems. Nonetheless an optical memory based on spin-wave storage at the single-photon level has not been shown in such a system to date, which is crucial for achieving the long storage times required for quantum repeaters. In this paper we show that it is possible to execute a complete atomic frequency comb (AFC) scheme, including spin-wave storage, with weak coherent pulses of $\overline{n}=2.5\ifmmode\pm\else\textpm\fi{}0.6$ photons per pulse. We discuss in detail the experimental steps required to obtain this result and demonstrate the coherence of a stored time-bin pulse. We show a noise level of $(7.1\ifmmode\pm\else\textpm\fi{}2.3)\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}3}$ photons per mode during storage, and this relatively low noise level paves the way for future quantum optics experiments using spin waves in rare-earth-doped crystals.
Quantum memories are a crucial technology for enabling large-scale quantum networks through synchronization of probabilistic operations. Such networks impose strict requirements on quantum memory, such as storage time, retrieval efficiency, bandwidth, and scalability. On- and off-resonant ladder protocols on warm atomic vapor platforms are promising candidates, combining efficient high-bandwidth operation with low-noise on-demand retrieval. However, their storage time is severely limited by motion-induced dephasing caused by the broad velocity distribution of atoms composing the vapor. In this paper, we demonstrate velocity selective optical pumping to overcome this decoherence mechanism. This will increase the achievable memory storage time of vapor memories. This technique can also be used for preparing arbitrarily shaped absorption profiles, for instance, preparing an atomic frequency comb absorption feature.
An optical quantum memory is a stationary device that is capable of storing and recreating photonic qubits with a higher fidelity than any classical device. Thus far, these two requirements have been fulfilled for polarization qubits in systems based on cold atoms and cryogenically cooled crystals. Here, we report a room-temperature memory capable of storing arbitrary polarization qubits with a signal-to-background ratio higher than 1 and an average fidelity surpassing the classical benchmark for weak laser pulses containing 1.6 photons on average, without taking into account non-unitary operation. Our results demonstrate that a common vapor cell can reach the low background noise levels necessary for polarization qubit storage using single-photon level light, and propels atomic-vapor systems towards a level of functionality akin to other quantum information processing architectures.