Diamonds used for qubit entanglement over distance

Takaaki Shimo-Oka

Alp Sipahigil, Michael Goldman, Alexey V. Akimov +6 more

C. E. Bradley, J. Randall, Remon Berrevoets +4 more

Ronald Hanson

Luka Trifunovic, Fabio L. Pedrocchi, Daniel Loss

Atomlike spin-based nitrogen-vacancy centers in diamond have emerged as a promising class of candidates for qubits in room-temperature quantum computing. Making them interact with each other in a controlled and scalable way even when they are separated over long distances is the next step. A new proposal shows that this goal can be achieved by coupling the spin qubits to a common ferromagnet and exploiting the fast traveling magnons in the ferromagnet as the agent mediating long-range qubit-qubit interactions.

Philip Hemmer, Mikhail D. Lukin

We are developing solid-state quantum repeaters for long-distance, secure quantum communication networks. These repeaters will combine long-range quantum entanglement, produced by optical measurements, with local few-qubit quantum processing and storage nodes. So far we have demonstrated all the key elements of the local quantum processors using nitrogen-vacancy (NV) color centers in diamond. These include multi-qubit entanglement, long storage times, and robustness against multiple re-initialization steps. Significantly, all these local operations were demonstrated at room temperature. Finally, we estimate that single shot readout should be achievable with optical plasmon wire coupling which would open the door to room-temperature few-qubit quantum computers.