Demonstration of a fully tunable entangling gate for continuous-variable one-way quantum computation

We introduce a fully tunable entangling gate for continuous-variable one-way quantum computation. We present a proof-of-principle demonstration by propagating two independent optical inputs through a three-mode linear cluster state and applying the gate in various regimes. The genuine quantum nature of the gate is confirmed by verifying the entanglement strength in the output state. Our protocol can be readily incorporated into efficient multimode interaction operations in the context of large-scale one-way quantum computation, as our tuning process is the generalization of cluster-state shaping.