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

Towards long-distance quantum communication using trapped ions and frequency qubits

Moji Ghadimi, Steven Connell, Jordan Scarabel, Kenji Shimizu, Erik W. Streed, Mirko Lobino

Published Dec 30, 2019• 0 citations
Publisher

Abstract

Quantum communication requires long-lived memories and robust communication qubits. Long-lived memories and high fidelity two qubit gates are demonstrated using atomic qubits. Frequency qubits are shown to be robust against noises present in long distance communications. In this project we are working towards using trapped 171Yb+ ions as memory qubits and frequency encoded photonic qubits as communication qubits to realise long distance quantum communication protocols.

DOI
10.1117/12.2540050

Related papers

Ion–photonic frequency qubit correlations for quantum networks

Steven C Connell, Jordan Scarabel, Elizabeth M Bridge +5 more

Efficiently scaling quantum networks to long ranges requires local processing nodes to perform basic computation and communication tasks. Trapped ions have demonstrated all the properties required for the construction of such a node, storing quantum information for up to 12 min, implementing deterministic high fidelity logic operations on one and two qubits, and ion–photon coupling. While most ions suitable for quantum computing emit photons in visible to near ultraviolet (UV) frequency ranges poorly suited to long-distance fibre optical based networking, recent experiments in frequency conversion provide a technological solution by shifting the photons to frequencies in the telecom band with lower attenuation for fused silica fibres. Encoding qubits in frequency rather than polarization makes them more robust against decoherence from thermal or mechanical noise due to the conservation of energy. To date, ion–photonic frequency qubit entanglement has not been directly shown. Here we demonstrate a frequency encoding ion–photon entanglement protocol in 171 Yb + with correlations equivalent to 92.4(8)% fidelity using a purpose-built UV hyperfine spectrometer. The same robustness against decoherence precludes our passive optical setup from rotating photonic qubits to unconditionally demonstrate entanglement, however it is sufficient to allow us to benchmark the quality of ion–UV photon correlations prior to frequency conversion to the telecom band.

arXiv:2104.05189•Journal of Physics B Atomic Molecular and Optical Physics•Sep 8, 2021•10 citations

Quantum Repeaters Based on Two-Species Trapped Ions

Sreraman Muralidharan, Siddhartha Santra, Liang Jiang +2 more

Trapped ions technology is the most promising candidate for construction of the large-scale quantum computers, quantum repeaters and quantum networks. Quantum networks require matter qubits with fast quantum gates and measurement, efficient coupling to photons and low gate error rates. There was growing progress in two-species ion trapping [1], where one ion acts as a communication qubit that can be efficiently entangled to photon and the other one used as excellent quantum memories allowing efficient local processing. However, the photonic interface needed for communication ions must not affect the state of the quantum memory ion. In a recent experimental breakthrough, the isolation between quantum memory ion (171Yb+) and communication ion (138Ba+) was achieved and a quantum state transfer between the ions has been demonstrated.

IEEE/LEOS Summer Topical Meetings•Jul 1, 2018•2 citations

Realization of a Crosstalk-Free Two-Ion Node for Long-Distance Quantum Networking

P.-C. Lai, Y. Wang, J.-X. Shi +14 more

Trapped atomic ions constitute one of the leading physical platforms for building the quantum repeater nodes to realize large-scale quantum networks. In a long-distance trapped-ion quantum network, it is essential to have crosstalk-free dual-type qubits: one type, called the communication qubit, to establish an entangling interface with telecom photons; and the other type, called the memory qubit, to store quantum information immune from photon scattering under entangling attempts. Here, we report the first experimental implementation of a telecom-compatible and crosstalk-free quantum network node based on two trapped ^{40}Ca^{+} ions. The memory qubit is encoded on a long-lived metastable level to avoid crosstalk with the communication qubit encoded in another subspace of the same ion species, and a quantum wavelength conversion module is employed to generate heralded ion-photon entanglement over a 12 km fiber. Our work therefore constitutes an important step toward the realization of quantum repeaters and long-distance quantum networks.

Physical Review Letters•Feb 19, 2025•10 citations

Quantum Logic Between Distant Trapped Ions

Steven Olmschenk, David Hayes, Dzmitry Matsukevich +3 more

Trapped atomic ions have proven to be one of the most promising candidates for the realization of quantum computation due to their long trapping times, excellent coherence properties, and exquisite control of the internal atomic states. Integrating ions (quantum memory) with photons (distance link) offers a unique path to large-scale quantum computation and long-distance quantum communication. In this article, we present a detailed review of the experimental implementation of a heralded photon-mediated quantum gate between remote ions, and the employment of this gate to perform a teleportation protocol between two ions separated by a distance of about one meter.

•Aug 4, 2013•18 citations

Error models for long-distance Qubit teleportation

Brent J. Yen, Jeffrey H. Shapiro

A recent proposal for realizing long-distance, high-fidelity qubit teleportation is reviewed. This quantum communication architecture relies on an ultrabright source of polarization-entangled photons plus a pair of trapped-atom quantum memories, and it is compatible with long-distance transmission over standard telecommunication fiber. Models are developed for assessing the effects of amplitude, phase, and frequency errors in the entanglement source, as well as fiber loss and imperfect polarization restoration, on the throughput and fidelity of the system.

IEEE Journal of Selected Topics in Quantum Electronics•Nov 1, 2003•6 citations

QUANTUM LOGIC BETWEEN DISTANT TRAPPED IONS

S. OLMSCHENK, David Hayes, D. N. MATSUKEVICH +3 more

Trapped atomic ions have proven to be one of the most promising candidates for the realization of quantum computation due to their long trapping times, excellent coherence properties, and exquisite control of the internal atomic states. Integrating ions (quantum memory) with photons (distance link) offers a unique path to large-scale quantum computation and long-distance quantum communication. In this article, we present a detailed review of the experimental implementation of a heralded photon-mediated quantum gate between remote ions, and the employment of this gate to perform a teleportation protocol between two ions separated by a distance of about one meter.

arXiv:0907.1702•International Journal of Quantum Information•Feb 1, 2010•17 citations
Quantum communication requires long-lived memories and robust communication qubits. Long-lived memories and high fidelity two qubit gates are demonstrated using atomic qubits. Frequency qubits are shown to be robust against noises present in long distance communications. In this project we are working towards using trapped 171Yb+ ions as memory qubits and frequency encoded photonic qubits as communication qubits to realise long distance quantum communication protocols.
Efficiently scaling quantum networks to long ranges requires local processing nodes to perform basic computation and communication tasks. Trapped ions have demonstrated all the properties required for the construction of such a node, storing quantum information for up to 12 min, implementing deterministic high fidelity logic operations on one and two qubits, and ion–photon coupling. While most ions suitable for quantum computing emit photons in visible to near ultraviolet (UV) frequency ranges poorly suited to long-distance fibre optical based networking, recent experiments in frequency conversion provide a technological solution by shifting the photons to frequencies in the telecom band with lower attenuation for fused silica fibres. Encoding qubits in frequency rather than polarization makes them more robust against decoherence from thermal or mechanical noise due to the conservation of energy. To date, ion–photonic frequency qubit entanglement has not been directly shown. Here we demonstrate a frequency encoding ion–photon entanglement protocol in 171 Yb + with correlations equivalent to 92.4(8)% fidelity using a purpose-built UV hyperfine spectrometer. The same robustness against decoherence precludes our passive optical setup from rotating photonic qubits to unconditionally demonstrate entanglement, however it is sufficient to allow us to benchmark the quality of ion–UV photon correlations prior to frequency conversion to the telecom band.
Trapped ions technology is the most promising candidate for construction of the large-scale quantum computers, quantum repeaters and quantum networks. Quantum networks require matter qubits with fast quantum gates and measurement, efficient coupling to photons and low gate error rates. There was growing progress in two-species ion trapping [1], where one ion acts as a communication qubit that can be efficiently entangled to photon and the other one used as excellent quantum memories allowing efficient local processing. However, the photonic interface needed for communication ions must not affect the state of the quantum memory ion. In a recent experimental breakthrough, the isolation between quantum memory ion (171Yb+) and communication ion (138Ba+) was achieved and a quantum state transfer between the ions has been demonstrated.
Trapped atomic ions constitute one of the leading physical platforms for building the quantum repeater nodes to realize large-scale quantum networks. In a long-distance trapped-ion quantum network, it is essential to have crosstalk-free dual-type qubits: one type, called the communication qubit, to establish an entangling interface with telecom photons; and the other type, called the memory qubit, to store quantum information immune from photon scattering under entangling attempts. Here, we report the first experimental implementation of a telecom-compatible and crosstalk-free quantum network node based on two trapped ^{40}Ca^{+} ions. The memory qubit is encoded on a long-lived metastable level to avoid crosstalk with the communication qubit encoded in another subspace of the same ion species, and a quantum wavelength conversion module is employed to generate heralded ion-photon entanglement over a 12 km fiber. Our work therefore constitutes an important step toward the realization of quantum repeaters and long-distance quantum networks.
Trapped atomic ions have proven to be one of the most promising candidates for the realization of quantum computation due to their long trapping times, excellent coherence properties, and exquisite control of the internal atomic states. Integrating ions (quantum memory) with photons (distance link) offers a unique path to large-scale quantum computation and long-distance quantum communication. In this article, we present a detailed review of the experimental implementation of a heralded photon-mediated quantum gate between remote ions, and the employment of this gate to perform a teleportation protocol between two ions separated by a distance of about one meter.
A recent proposal for realizing long-distance, high-fidelity qubit teleportation is reviewed. This quantum communication architecture relies on an ultrabright source of polarization-entangled photons plus a pair of trapped-atom quantum memories, and it is compatible with long-distance transmission over standard telecommunication fiber. Models are developed for assessing the effects of amplitude, phase, and frequency errors in the entanglement source, as well as fiber loss and imperfect polarization restoration, on the throughput and fidelity of the system.
Trapped atomic ions have proven to be one of the most promising candidates for the realization of quantum computation due to their long trapping times, excellent coherence properties, and exquisite control of the internal atomic states. Integrating ions (quantum memory) with photons (distance link) offers a unique path to large-scale quantum computation and long-distance quantum communication. In this article, we present a detailed review of the experimental implementation of a heralded photon-mediated quantum gate between remote ions, and the employment of this gate to perform a teleportation protocol between two ions separated by a distance of about one meter.