Entanglement of trapped-ion qubits over a 50 km-long fiber link

10 Sept 2026, 10:30
20m
Short Talk (15min) Quantum Information & Computing Quantum Computing

Speaker

Armin Winkler (Universität Innsbruck)

Description

Quantum networks of registers of atoms have promising applications in cryptography, distributed computing, sensing, and clock synchronization. The realization of such networks requires the establishment of entanglement between atoms tens of kilometers apart. We recently performed an experiment to entangle two trapped atomic ions separated by 50 km of spooled optical fiber. Preliminary analysis of the data shows clear entanglement between the two ions. The entanglement is heralded by the detection of two photons – each collected from an ion using an optical cavity. In my presentation I will detail the experimental setup, give a quantitative analysis of our results in terms of the achieved Bell state fidelity and rates, and present our understanding of the main limiting factors. A key feature of our approach is the use of the two-photon click scheme, which does not require interferometric stabilization of the 50 km fiber path. Our results therefore open the door to robust metropolitan-scale networks of trapped-ion quantum processors, sensor arrays and clocks.

Academic level PhD student

Authors

Armin Winkler (Universität Innsbruck) Prof. Benjamin Lanyon (Universität Innsbruck) F. Kodakkat Mr Felix Bernecker (Universität Innsbruck) Dr Josef Schupp (AQT) Dr Miao Cai (Universität Innsbruck) Ms Moming Jia (Universität Innsbruck) Mr Pascal Wintermeyer (Universität Innsbruck) Mr Shivam Sawarn (Universität Innsbruck) Dr Simon Baier (Universität Innsbruck) Prof. Tracy Northup (Universität Innsbruck) Dr Viktor Krutyanskiy (Universität Innsbruck)

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