Quantum Repeaters Based on Two-Species Trapped Ions
Trapped ions technology is the most promising candidate for construction of the large-scale quantum computers, quantum repeaters and quantum networks. Quantum networks require matter qubits with fast quantum gates and measurement, efficient coupling to photons and low gate error rates. There was growing progress in two-species ion trapping [1], where one ion acts as a communication qubit that can be efficiently entangled to photon and the other one used as excellent quantum memories allowing efficient local processing. However, the photonic interface needed for communication ions must not affect the state of the quantum memory ion. In a recent experimental breakthrough, the isolation between quantum memory ion (171Yb+) and communication ion (138Ba+) was achieved and a quantum state transfer between the ions has been demonstrated.
