Researchers achieved entanglement between the nuclei (i.e. the “hearts”) of two phosphorus atoms embedded in a silicon chip, separated by ~20 nanometres.
They used the nuclear spins of those atoms to store quantum information (good coherence, well-shielded).
Communication/interaction between the nuclei is mediated via electrons (which couple to each nucleus) using a technique called a geometric gate.
This is a step beyond previous setups where multiple nuclei shared a single electron (i.e. were much more closely tied). Here, the method works even when nuclei are not on the same electron.
Because 20 nm is comparable to dimensions used in modern silicon transistor manufacturing, this suggests compatibility with existing silicon-chip fabrication technologies.
The work paves the way toward scalable quantum computers using long-lived nuclear spin qubits—combining good coherence (from nuclei) with more flexible control (via electrons).