Kilometer-Scale Ion-Photon Entanglement with a Metastable ${}^{88}$Sr${}^{+}$ Qubit

Abstract

We demonstrate entanglement between the polarization of an infrared photon and a metastable ${}^{88}$Sr${}^{+}$ ion qubit. This entanglement persists after transmitting the photon over a $2.8$km long commercial fiber deployed in an urban environment. Tomography of the ion-photon entangled state yields a fidelity of $0.949(4)$ within the laboratory and $0.929(5)$ after fiber transmission, not corrected for readout errors. Our results establish the Strontium ion as a promising candidate for metropolitan-scale quantum networking based on an atomic transition at $1092$nm, a wavelength compatible with existing telecom fiber infrastructure.

References in corpus (39)

• Quantum Cryptography
• Experimental loophole-free violation of a Bell inequality using entangled electron spins separated by 1.3 km
• Device-independent security of quantum cryptography against collective attacks
• An Elementary Quantum Network of Single Atoms in Optical Cavities
• Large Scale Modular Quantum Computer Architecture with Atomic Memory and Photonic Interconnects
• Event-Ready Bell Test Using Entangled Atoms Simultaneously Closing Detection and Locality Loopholes
• Longer-Baseline Telescopes Using Quantum Repeaters
• Development of Quantum InterConnects for Next-Generation Information Technologies
• Robust long-distance entanglement and a loophole-free Bell test with ions and photons
• Single ion-qubit exceeding one hour coherence time
• Modular Entanglement of Atomic Qubits using both Photons and Phonons
• Experimental device-independent quantum key distribution between distant users
• Entanglement of Nanophotonic Quantum Memory Nodes in a Telecom Network
• Quantum teleportation from a telecom-wavelength photon to a solid-state quantum memory
• Tunable ion-photon entanglement in an optical cavity
• Entangling single atoms over 33 km telecom fibre
• Entanglement of trapped-ion qubits separated by 230 meters
• Wide-band quantum interface for visible-to-telecommunication wavelength conversion
• High-fidelity entanglement between a trapped ion and a telecom photon via quantum frequency conversion
• Distributed Quantum Computing across an Optical Network Link
• Quantum inference of states and processes
• Long-distance distribution of atom-photon entanglement at telecom wavelength
• Light-matter entanglement over 50 km of optical fibre
• A quantum network of entangled optical atomic clocks
• Quantum networks with neutral atom processing nodes
• Entanglement between a diamond spin qubit and a photonic time-bin qubit at telecom wavelength
• Metropolitan-scale heralded entanglement of solid-state qubits
• Entangling metropolitan-distance separated quantum memories
• Verifiable blind quantum computing with trapped ions and single photons
• Protocols and Techniques for a Scalable Atom--Photon Quantum Network
• High-fidelity remote entanglement of trapped atoms mediated by time-bin photons
• Single-qubit gates with errors at the $10^{-7}$ level
• Scalable, high-fidelity all-electronic control of trapped-ion qubits
• Fast photon-mediated entanglement of continuously-cooled trapped ions for quantum networking
• Spin-photon entanglement with direct photon emission in the telecom C-band
• Optimisation of Scalable Ion-Cavity Interfaces for Quantum Photonic Networks
• Parallelized telecom quantum networking with a ytterbium-171 atom array
• Ion-Photonic Frequency Qubit Correlations for Quantum Networks
• Mitigation of birefringence in cavity-based quantum networks using frequency-encoded photons

Cited by in corpus (1)

• BIFROST: A First-Principles Model of Polarization Mode Dispersion in Optical Fiber