The work demonstrates control over entanglement between different atomic species, a key step toward versatile quantum technologies and networks, while advancing quantum networking and distributed quantum information processing by combining multi-atom entanglement with inter-species coherence.

Calcium states show reduced sensitivity to magnetic-field noise compared with strontium, underpinning an extended entanglement lifetime.

Researchers created shared quantum states involving up to four atoms and extended the entanglement lifetime to over 10 seconds using calcium atoms, marking a major improvement over millisecond timescales seen with strontium alone.

Extending entanglement lifetime beyond 10 seconds enables sustained quantum connections between multiple atoms and supports coordination between separate quantum processors, i.e., a distributed quantum computer.

Different atomic species offer distinct advantages, and multi-species entanglement allows leveraging these strengths for computing, sensing, and timekeeping.

The study, published in Physical Review Letters under the title Multipartite mixed-species entanglement over a quantum network, highlights potential applications in quantum sensing and timekeeping beyond computation.

A team from the University of Oxford demonstrated entanglement between strontium and calcium atoms across a quantum network, enabling inter-species quantum linking.