Distributed quantum computing across an optical network link

Building a large-scale quantum computer may only be feasible by combining the computing power of networked quantum processing modules, enabling all-to-all connectivity through quantum gate teleportation. In this work, we present the first demonstration of distributed quantum computing between two photonically interconnected trapped-ion modules separated by approximately two meters. Each module comprises dedicated network and circuit qubits. Utilising heralded shared entanglement between network qubits, we deterministically teleport controlled-Z gates between distant circuit qubits in separate modules, achieving a fidelity of 86.1(9)%. We showcase the capability to execute multiple consecutive teleported controlled-Z gates and provide benchmarks for the performance of iSWAP and SWAP circuits, which involve two and three instances of gate teleportation, respectively. Additionally, we demonstrate Grover's search algorithm on a distributed two-qubit register, marking the first implementation of a distributed quantum algorithm that includes more than one non-local two-qubit gate, and achieving a success rate of 71(1)%. These results highlight the potential of networked quantum processing modules for scalable quantum computation, and we show here recent progress extending this architecture to quantum error detection protocols and entanglement distillation.