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

Quantum 2.0 Conference and Exhibition

Storage of qubits in a solid-state quantum memory array

Markus Teller, Susana Plascencia, Cristina Sastre Jachimska, Samuele Grandi, Hugues de Riedmatten

Published Jan 1, 2025• 0 citations
Publisher

Abstract

We demonstrate the storage of path and time-bin qubits in solid-state quantum memories. Our system stores up to 250 modes with faint laser pulses and validates performance using single photons from a nonlinear source.
DOI
10.1364/quantum.2025.qm4a.3

Related papers

Quantum Storage of Qubits in an Array of Independently Controllable Solid-State Quantum Memories

Markus Teller, Susana Plascencia, Samuele Grandi +1 more

Random-access quantum memories may offer computational advantages for quantum computers and networks. In this paper, we advance arrays of solid-state quantum memories toward their usage as random-access quantum memory. We perform quantum storage of path and time-bin qubits implemented with weak coherent states at the single-photon level, in an array of ten temporally multiplexed memory cells with controllable addressing. The qubits can be stored in arbitrary combinations of memory cells, from which they are read out on demand. We find average fidelities of 95 − 2 + 2 % for path qubits and 91 − 2 + 2 % for time-bin qubits. The measured fidelities violate the classical bounds for both encodings and for all ten cells. We also sequentially store a time-bin qubit in two different memory cells, maintain both qubits simultaneously in the array, and perform a collective readout. The individual control paired with high storage fidelity represents a significant advance toward a solid-state random-access quantum memory for quantum repeaters and photonic quantum processors.

arXiv:2509.11910•Physical Review X•Jul 8, 2025•3 citations

Solid State Spin-Wave Quantum Memory for Time-Bin Qubits

Mustafa Gündoğan, Patrick M. Ledingham, Kutlu Kutluer +2 more

We demonstrate the first solid-state spin-wave optical quantum memory with on-demand read-out. Using the full atomic frequency comb scheme in a ${\mathrm{Pr}}^{3+}\ensuremath{\mathbin:}{\mathrm{Y}}_{2}{\mathrm{SiO}}_{5}$ crystal, we store weak coherent pulses at the single-photon level with a signal-to-noise ratio $>10$. Narrow-band spectral filtering based on spectral hole burning in a second ${\mathrm{Pr}}^{3+}\ensuremath{\mathbin:}{\mathrm{Y}}_{2}{\mathrm{SiO}}_{5}$ crystal is used to filter out the excess noise created by control pulses to reach an unconditional noise level of $(2.0\ifmmode\pm\else\textpm\fi{}0.3)\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}3}$ photons per pulse. We also report spin-wave storage of photonic time-bin qubits with conditional fidelities higher than achievable by a measure and prepare strategy, demonstrating that the spin-wave memory operates in the quantum regime. This makes our device the first demonstration of a quantum memory for time-bin qubits, with on-demand read-out of the stored quantum information. These results represent an important step for the use of solid-state quantum memories in scalable quantum networks.

arXiv:1501.03980•Physical Review Letters•Jun 12, 2015•213 citations

Rare-earth quantum memories for single photons and entanglement

Imam Usmani

The ability of storing and retrieving quantum states of light is an important experimental challenge in quantum information science. A powerful quantum memory for light is required in a quantum repeater, which would allow long distance (>500km) quantum communications. To be implemented in such application, the quantum memory must allow on-demand readout, with high fidelity and efficiency, and a long storage time. Additionally a multimode capacity (for temporal or spatial modes) would allow multiplexing. Our approaches focus on rare-earth doped crystals, i.e. solid state quantum memory. I present, in this work, our contributions for a solid-state quantum storage, with good performances in every criteria. In particular, I present the preservation of quantum entanglement during the storage, which paves the way for the implementation of quantum memories in quantum repeaters.

•Jan 1, 2013•0 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

Entanglement and nonlocality between disparate solid-state quantum memories mediated by photons

Marcel. li Grimau Puigibert, Mohsen Falamarzi Askarani, Jacob H. Davidson +7 more

This work demonstrates entanglement preservation of entangled time-bin qubits after storage and reemission from two disparate solid-state quantum memories. This is implemented in rare-earth ion-doped host materials and hinge on atomic frequency comb protocol, and may open up applications on quantum repeaters

arXiv:1905.08184•Physical Review Research•Jan 13, 2020•37 citations

All-optical ultrawide-bandwidth quantum buffer

Nathan T. Arnold, Michelle Victora, M. E. Goggin +1 more

Quantum optical memories are a key component in a variety of quantum information applications, from extending quantum communication channels to building high-efficiency single-photon sources to enabling protocols requiring multiple synchronized qubits. However, most current photon storage systems utilize light-matter interactions and are therefore not broadband; meanwhile the available broader-bandwidth photon storage systems operate with somewhat shorter storage times or require cryogenic operation. Here we develop a system with multiplexed free-space storage cavities, able to store single photons with high efficiency over variable delays, up to 12.5 µs, and over multiple nanometers bandwidth at room temperature. The system can store multiple qubits encoded in various degrees of freedom (e.g., time-bin, and polarization) simultaneously. The work presented here has demonstrated storage of polarization states for 1.25 µs and retrieval through single-mode fiber with a state fidelity >99% and efficiency 82%.

Photonics for Quantum (PfQ)•Jul 9, 2021•2 citations
Random-access quantum memories may offer computational advantages for quantum computers and networks. In this paper, we advance arrays of solid-state quantum memories toward their usage as random-access quantum memory. We perform quantum storage of path and time-bin qubits implemented with weak coherent states at the single-photon level, in an array of ten temporally multiplexed memory cells with controllable addressing. The qubits can be stored in arbitrary combinations of memory cells, from which they are read out on demand. We find average fidelities of 95 − 2 + 2 % for path qubits and 91 − 2 + 2 % for time-bin qubits. The measured fidelities violate the classical bounds for both encodings and for all ten cells. We also sequentially store a time-bin qubit in two different memory cells, maintain both qubits simultaneously in the array, and perform a collective readout. The individual control paired with high storage fidelity represents a significant advance toward a solid-state random-access quantum memory for quantum repeaters and photonic quantum processors.
We demonstrate the first solid-state spin-wave optical quantum memory with on-demand read-out. Using the full atomic frequency comb scheme in a ${\mathrm{Pr}}^{3+}\ensuremath{\mathbin:}{\mathrm{Y}}_{2}{\mathrm{SiO}}_{5}$ crystal, we store weak coherent pulses at the single-photon level with a signal-to-noise ratio >10>10>10. Narrow-band spectral filtering based on spectral hole burning in a second ${\mathrm{Pr}}^{3+}\ensuremath{\mathbin:}{\mathrm{Y}}_{2}{\mathrm{SiO}}_{5}$ crystal is used to filter out the excess noise created by control pulses to reach an unconditional noise level of $(2.0\ifmmode\pm\else\textpm\fi{}0.3)\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}3}$ photons per pulse. We also report spin-wave storage of photonic time-bin qubits with conditional fidelities higher than achievable by a measure and prepare strategy, demonstrating that the spin-wave memory operates in the quantum regime. This makes our device the first demonstration of a quantum memory for time-bin qubits, with on-demand read-out of the stored quantum information. These results represent an important step for the use of solid-state quantum memories in scalable quantum networks.
The ability of storing and retrieving quantum states of light is an important experimental challenge in quantum information science. A powerful quantum memory for light is required in a quantum repeater, which would allow long distance (>500km) quantum communications. To be implemented in such application, the quantum memory must allow on-demand readout, with high fidelity and efficiency, and a long storage time. Additionally a multimode capacity (for temporal or spatial modes) would allow multiplexing. Our approaches focus on rare-earth doped crystals, i.e. solid state quantum memory. I present, in this work, our contributions for a solid-state quantum storage, with good performances in every criteria. In particular, I present the preservation of quantum entanglement during the storage, which paves the way for the implementation of quantum memories in quantum repeaters.
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.
Quantum optical memories are a key component in a variety of quantum information applications, from extending quantum communication channels to building high-efficiency single-photon sources to enabling protocols requiring multiple synchronized qubits. However, most current photon storage systems utilize light-matter interactions and are therefore not broadband; meanwhile the available broader-bandwidth photon storage systems operate with somewhat shorter storage times or require cryogenic operation. Here we develop a system with multiplexed free-space storage cavities, able to store single photons with high efficiency over variable delays, up to 12.5 µs, and over multiple nanometers bandwidth at room temperature. The system can store multiple qubits encoded in various degrees of freedom (e.g., time-bin, and polarization) simultaneously. The work presented here has demonstrated storage of polarization states for 1.25 µs and retrieval through single-mode fiber with a state fidelity >99% and efficiency 82%.