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

Spin-dynamics of telecom-band optically addressable single Er3+ ions in CaWO4 at millikelivin temepratures

Ashwin K. Boddeti, Adam T. Turflinger, Joseph Alexander, Sebastian P. Horvath, Mehmet T. Uysal, Haitong Xu, Łukasz Dusanowski, Salim Ourari, Cady Feng, R. J. Cava, Nathalie P. de Leon, Jeff D. Thompson

Published Jan 1, 2025• 0 citations
Publisher

Abstract

Single Er3+ ions in CaWO4 coupled to nanophotonic cavities enable indistinguishable single-photon emission and spin-photon entanglement in the telecom band, forming building blocks for quantum repeater networks. However, spin decoherence from paramagnetic impurities limits fidelity. We investigate spin dynamics of near-surface Er ions (~10-15 nm from surface) as a step toward quantum repeaters and memory.

DOI
10.1364/cleo_fs.2025.ff101_7

Related papers

Spin-Photon Entanglement of a Single Er 3 + Ion in the Telecom Band

Mehmet T. Uysal, Łukasz Dusanowski, Haitong Xu +5 more

Entanglement between photons and a quantum memory is a key component of quantum repeaters, which allow long-distance quantum entanglement distribution in the presence of fiber losses. Spin-photon entanglement has been implemented with a number of different atomic and solid-state qubits with long spin coherence times, but none directly emit photons into the 1.5 − μ m telecom band where losses in optical fibers are minimized. Here, we demonstrate spin-photon entanglement using a single rare earth ion in the solid-state Er 3 + coupled to a silicon nanophotonic cavity, which directly emits photons at 1532.6 nm. We infer an entanglement fidelity of 73(3)% after propagating through 15.6 km of optical fiber. This work opens the door to large-scale quantum networks based Er 3 + ions, leveraging scalable silicon device fabrication and spectral multiplexing.

arXiv:2406.06515•Physical Review X•Mar 26, 2025•36 citations

Atomic Source of Single Photons in the Telecom Band

Alan Dibos, Mouktik Raha, Christopher M. Phenicie +1 more

Single atoms and atomlike defects in solids are ideal quantum light sources and memories for quantum networks. However, most atomic transitions are in the ultraviolet-visible portion of the electromagnetic spectrum, where propagation losses in optical fibers are prohibitively large. Here, we observe for the first time the emission of single photons from a single Er^{3+} ion in a solid-state host, whose optical transition at 1.5 μm is in the telecom band, allowing for low-loss propagation in optical fiber. This is enabled by integrating Er^{3+} ions with silicon nanophotonic structures, which results in an enhancement of the photon emission rate by a factor of more than 650. Dozens of distinct ions can be addressed in a single device, and the splitting of the lines in a magnetic field confirms that the optical transitions are coupled to the electronic spin of the Er^{3+} ions. These results are a significant step towards long-distance quantum networks and deterministic quantum logic for photons based on a scalable silicon nanophotonics architecture.

arXiv:1711.10368•Physical Review Letters•Jun 11, 2018•330 citations

Spin Dynamics of Single Er 3+ Ions in a Silicon Nanophotonic Cavity

Songtao Chen, Mouktik Raha, Christopher M. Phenicie +2 more

Magnetic field orientation and strength dependent spin dynamics is studied for the 1.536 $\mu \mathrm{m}$ telecom transitions of single Er3+ ions in Y 2 SiO 5 . Long spin $T_{1}=2$ seconds is measured from ground state Zeeman spin levels. © 2019 The Author(s)

Conference on Lasers and Electro-Optics•May 5, 2019•0 citations

Quantum repeater segment with free-space coupled co-trapped ions using telecom photon interference

Max Bergerhoff, Pascal Baumgart, Christian Haen +5 more

A quantum repeater segment is a basic building block of a quantum repeater, generating buffered entanglement of quantum memories to connect quantum repeater cells. It also enables the connection between quantum computers. In the implementation we present here, photons emitted from two co-trapped free-space coupled $^{40}$Ca$^+$ ions are converted to the telecom-C band and interfered after transmission over 440$\,$m of optical fiber (220$\,$m per arm), where a photonic Bell measurement is performed to create entanglement between the memories. With this scheme we generate an entangled $\left|Ψ^+\right\rangle$ Bell state with $\ge 68(8)\,$% fidelity, highlighting trapped $^{40}$Ca$^+$ ions as a promising quantum repeater hardware platform.

quant-pharXiv:2606.12313•Jun 11, 2026•0 citations

Stark Tuning of Telecom Single-Photon Emitters Based on a Single Er3+

Jian-Yin Huang, Peng-Jun Liang, Liang Zheng +7 more

The implementation of scalable quantum networks requires photons at the telecom band and long-lived spin coherence. The single Er3+ in solid-state hosts is an important candidate that fulfills these critical requirements simultaneously. However, to entangle distant Er3+ ions through photonic connections, the emission frequency of individual Er3+ in solid-state matrix must be the same, which is challenging because the emission frequency of Er3+ depends on its local environment. Herein, we propose and experimentally demonstrate the Stark tuning of the emission frequency of a single Er3+ in a Y2SiO5 crystal by employing electrodes interfaced with a silicon photonic crystal cavity. We obtain a Stark shift of 182.9±0.8 MHz, which is approximately 27 times of the optical emission linewidth, demonstrating promising applications in tuning the emission frequency of independent Er3+ into the same spectral channels. Our results provide a useful solution for construction of scalable quantum networks based on single Er3+ and a universal tool for tuning emission of individual rare-earth ions.

arXiv:2305.01216•Chinese Physics Letters•May 27, 2023•19 citations

Frequency Tunable, Cavity-Enhanced Single Erbium Quantum Emitter in the Telecom Band

Yong Hui Yu, Dorian Oser, Gaia Da Prato +7 more

Single quantum emitters embedded in solid-state hosts are an ideal platform for realizing quantum information processors and quantum network nodes. Among the currently investigated candidates, Er^{3+} ions are particularly appealing due to their 1.5 μm optical transition in the telecom band as well as their long spin coherence times. However, the long lifetimes of the excited state-generally in excess of 1 ms-along with the inhomogeneous broadening of the optical transition result in significant challenges. Photon emission rates are prohibitively small, and different emitters generally create photons with distinct spectra, thereby preventing multiphoton interference-a requirement for building large-scale, multinode quantum networks. Here we solve this challenge by demonstrating for the first time linear Stark tuning of the emission frequency of a single Er^{3+} ion. Our ions are embedded in a lithium niobate crystal and couple evanescently to a silicon nanophotonic crystal cavity that provides a strong increase of the measured decay rate. By applying an electric field along the crystal c axis, we achieve a Stark tuning greater than the ion's linewidth without changing the single-photon emission statistics of the ion. These results are a key step towards rare earth ion-based quantum networks.

arXiv:2304.14685•Physical Review Letters•Oct 23, 2023•35 citations
Single Er3+ ions in CaWO4 coupled to nanophotonic cavities enable indistinguishable single-photon emission and spin-photon entanglement in the telecom band, forming building blocks for quantum repeater networks. However, spin decoherence from paramagnetic impurities limits fidelity. We investigate spin dynamics of near-surface Er ions (~10-15 nm from surface) as a step toward quantum repeaters and memory.
Entanglement between photons and a quantum memory is a key component of quantum repeaters, which allow long-distance quantum entanglement distribution in the presence of fiber losses. Spin-photon entanglement has been implemented with a number of different atomic and solid-state qubits with long spin coherence times, but none directly emit photons into the 1.5 − μ m telecom band where losses in optical fibers are minimized. Here, we demonstrate spin-photon entanglement using a single rare earth ion in the solid-state Er 3 + coupled to a silicon nanophotonic cavity, which directly emits photons at 1532.6 nm. We infer an entanglement fidelity of 73(3)% after propagating through 15.6 km of optical fiber. This work opens the door to large-scale quantum networks based Er 3 + ions, leveraging scalable silicon device fabrication and spectral multiplexing.
Single atoms and atomlike defects in solids are ideal quantum light sources and memories for quantum networks. However, most atomic transitions are in the ultraviolet-visible portion of the electromagnetic spectrum, where propagation losses in optical fibers are prohibitively large. Here, we observe for the first time the emission of single photons from a single Er^{3+} ion in a solid-state host, whose optical transition at 1.5 μm is in the telecom band, allowing for low-loss propagation in optical fiber. This is enabled by integrating Er^{3+} ions with silicon nanophotonic structures, which results in an enhancement of the photon emission rate by a factor of more than 650. Dozens of distinct ions can be addressed in a single device, and the splitting of the lines in a magnetic field confirms that the optical transitions are coupled to the electronic spin of the Er^{3+} ions. These results are a significant step towards long-distance quantum networks and deterministic quantum logic for photons based on a scalable silicon nanophotonics architecture.
Magnetic field orientation and strength dependent spin dynamics is studied for the 1.536 μm\mu \mathrm{m}μm telecom transitions of single Er3+ ions in Y 2 SiO 5 . Long spin T1=2T_{1}=2T1​=2 seconds is measured from ground state Zeeman spin levels. © 2019 The Author(s)
A quantum repeater segment is a basic building block of a quantum repeater, generating buffered entanglement of quantum memories to connect quantum repeater cells. It also enables the connection between quantum computers. In the implementation we present here, photons emitted from two co-trapped free-space coupled 40^{40}40Ca+^++ ions are converted to the telecom-C band and interfered after transmission over 440 \,m of optical fiber (220 \,m per arm), where a photonic Bell measurement is performed to create entanglement between the memories. With this scheme we generate an entangled ∣Ψ+⟩\left|Ψ^+\right\rangle∣Ψ+⟩ Bell state with ≥68(8) \ge 68(8)\,≥68(8)% fidelity, highlighting trapped 40^{40}40Ca+^++ ions as a promising quantum repeater hardware platform.
The implementation of scalable quantum networks requires photons at the telecom band and long-lived spin coherence. The single Er3+ in solid-state hosts is an important candidate that fulfills these critical requirements simultaneously. However, to entangle distant Er3+ ions through photonic connections, the emission frequency of individual Er3+ in solid-state matrix must be the same, which is challenging because the emission frequency of Er3+ depends on its local environment. Herein, we propose and experimentally demonstrate the Stark tuning of the emission frequency of a single Er3+ in a Y2SiO5 crystal by employing electrodes interfaced with a silicon photonic crystal cavity. We obtain a Stark shift of 182.9±0.8 MHz, which is approximately 27 times of the optical emission linewidth, demonstrating promising applications in tuning the emission frequency of independent Er3+ into the same spectral channels. Our results provide a useful solution for construction of scalable quantum networks based on single Er3+ and a universal tool for tuning emission of individual rare-earth ions.
Single quantum emitters embedded in solid-state hosts are an ideal platform for realizing quantum information processors and quantum network nodes. Among the currently investigated candidates, Er^{3+} ions are particularly appealing due to their 1.5 μm optical transition in the telecom band as well as their long spin coherence times. However, the long lifetimes of the excited state-generally in excess of 1 ms-along with the inhomogeneous broadening of the optical transition result in significant challenges. Photon emission rates are prohibitively small, and different emitters generally create photons with distinct spectra, thereby preventing multiphoton interference-a requirement for building large-scale, multinode quantum networks. Here we solve this challenge by demonstrating for the first time linear Stark tuning of the emission frequency of a single Er^{3+} ion. Our ions are embedded in a lithium niobate crystal and couple evanescently to a silicon nanophotonic crystal cavity that provides a strong increase of the measured decay rate. By applying an electric field along the crystal c axis, we achieve a Stark tuning greater than the ion's linewidth without changing the single-photon emission statistics of the ion. These results are a key step towards rare earth ion-based quantum networks.