Individual qubits stored in trapped calcium ions, each entangled with separate photons, form scalable nodes for quantum networks

https://phys.org/news/2025-08-calcium-ions-entangled-photons-scalable.html

"prototype: node using string of 10 calcium ions in quantum computer... also applicable to quantum sensors... adjusting electric fields, ions placed 1 by 1 into optical cavity, then, finely tuned laser pulse triggered emission of single photon whose polarization entangled with ion's state... stream of photons, each tied to a different ion-qubit in register... 92% entanglement fidelity... scalable: registers potentially linking hundreds of ion-qubits to individual photons, connecting entire quantum processors across continents"