Parallel and heralded multiqubit entanglement generation for quantum networks

Abstract

Quantum networks involving multiqubit entanglement allow exciting applications in quantum communication, quantum sensing, and distributed quantum computation. The efficiency of nonlocal entanglement generation through optical channels drops exponentially with the distance between network nodes. We present a parallel and heralded protocol for generating distributed multiqubit entanglement across multiple nodes. This is achieved by using a high-dimensional single photon that works as a common-data bus connecting all stationary qubits (i.e., silicon-vacancy electron spins), each of which is coupled to a single-sided optical cavity. Parallel multiqubit entangled states are heralded by the detection of the single photon after it interacts with each stationary qubit and passes through each photonic modulation circuit. This parallel protocol can significantly improve the efficiency of distributed entanglement generation and provides a viable route towards distributed multinode quantum networks.