Long-Distance Entanglement of Spin Qubits via Ferromagnet

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.