Coherent control of a superconducting qubit using light*

Quantum science and technology promise the realization of a powerful computational resource that relies on a network of quantum processors connected with low loss and low noise communication channels capable of distributing entangled states. While superconducting microwave qubits (∼3-8 GHz) operating in cryogenic environments have emerged as promising candidates for quantum processor nodes due to their strong Josephson nonlinearity and low loss, the information between spatially separated processor nodes will likely be carried at room temperature via telecommunication photons (200 THz) propagating in low loss optical fibers. Transduction of quantum information between these disparate frequencies is therefore critical to leverage the advantages of each platform by interfacing quantum resources. Here, we demonstrate coherent optical control of a superconducting qubit. We achieve this by developing a microwave-optical quantum transducer that operates with up to 1.18% conversion efficiency (1.16% cooperativity) and demonstrate optically-driven Rabi oscillations (2.27 MHz) in a superconducting qubit without impacting qubit coherence times (800 ns). Finally, we discuss outlooks towards using the transducer to network quantum processor nodes.