How Diamonds Communicate Over Distance express
Two artificial diamonds act like tuning forks. Inside each, a carbon-13 atom, a quantum bit. Nearby, a lattice defect, like a sensitive ear, reads the vibrations of this atom. A light pulse traveling through optical fiber at the speed of light makes two distant atoms “sound” in unison: this creates entanglement. Now, a change in one instantly resonates in the other, even if they're in separate rooms.
To transmit a specific computational command, physicists use a protocol similar to teleportation: not the atom itself is transferred, but its state. First, the entangled pair acts as a link. Then one qubit is measured, akin to sending a text message with instructions: which notes the second tuning fork should play. That one immediately reproduces the prescribed “melody.” This is how the CNOT gate operated — a key element of any processor. There were no glitches: ultrafast electronics corrected each step in real time.
The success is cemented by creating complex entanglement for four qubits. The experiment builds on the ideas of Charles Bennett and Anton Zeilinger but implemented in mass-produced diamond chips. Surprisingly, such quantum communication doesn't require giant refrigerators — diamond qubits operate at room temperature. This opens the path to secure data transmission networks and distributed computing, where entropy (a measure of disorder) is no longer an enemy but a helper.
Original abstract
as written by the authors arXiv:2601.04848
Quantum networks connecting quantum processing nodes via photonic links enable distributed and modular quantum computation. In this framework, quantum gates between remote qubits can be realized using quantum teleportation protocols. The essential requirements for such non-local gates are remote entanglement, local quantum logic within each processor, and classical communication between nodes to perform operations based on measurement outcomes. Here, we demonstrate an unconditional Controlled-NOT quantum gate between remote diamond-based qubit devices. The control and target qubits are Carbon-13 nuclear spins, while NV electron spins enable local logic, readout, and remote entanglement generation. We benchmark the system by creating a Greenberger-Horne-Zeilinger state, showing genuine 4-partite entanglement shared between nodes. Using deterministic logic, single-shot readout, and real-time feed-forward, we implement non-local gates without post-selection. These results demonstrate a key capability for solid-state quantum networks, enabling exploration of distributed quantum computing and testing of complex network protocols on fully integrated systems.
Natural carbon contains only 1% of the needed isotope carbon-13, so diamonds are grown with an artificially increased fraction of this 'quantum' atom for experiments.
Science fiction promises teleportation of objects, but the real quantum version only transfers information about an atom's state, as if you copied a song file without sending the player itself.