Entangling operations in a quantum repeater node using synchronized fast adiabatic pulses

Abstract Solid-state rare-earth ions are promising candidates for implementing repeater nodes for quantum networks. However, state-of-the-art quantum nodes use only a single qubit per node, which greatly limits the functionality of the node and the scalability of the network. Here, we propose a scheme that utilizes a hybrid system of two ion qubits coupled to a nanophotonic cavity as a quantum node. Simultaneously applying a fast adiabatic pulse to the two ions can lead to an effective interaction between the two ion spin qubits by exchanging virtual photons in the cavity. Using this interaction, a controlled phase gate between the two ion qubits can be realized with a fidelity of 99.6%. Further utilizing this interaction, entangled states within the node can be generated deterministically and with high fidelity, and are robust to a variety of noises and fluctuations. These results pave the way for fully functional quantum repeater nodes based on solid-state rare-earth ions.