Phase-tuned entangled state generation between distant spin qubits

Entanglement between distant nodes is essential for the successful realisation of a distributed quantum network. Photon-mediated entanglement has recently been demonstrated in atomic [1] and diamond defect systems [2] and, very recently, using heavy hole spins in quantum dots [3]. However, until now controlled creation of entangled states with arbitrary phase had yet to be demonstrated in these systems. Here we demonstrate the high frequency creation of Bell states with arbitrary phase using electron-spin qubits confined to distant self-assembled InGaAs quantum dots (QD).