Towards efficient electro-optic transduction in thin film lithium niobate

Promising qubit technologies couple to electromagnetic waves with frequencies that span five orders of magnitude. For example, superconducting microwave circuits and trapped atoms couple to microwave and optical transitions, respectively. Transduction of quantum information between these disparate frequencies is therefore critical to interface quantum resources and leverage advantages different platforms. Moreover, this allows cryogenically cooled superconducting qubits to be coupled to optical qubits which operate at room temperature and travel long distances by low-loss fibers. Cavity electro-optics is a promising approach for transduction between microwave and optical quanta due to a wide transduction bandwidth as well as potential for highly efficient and low noise operation. We present a cavity electro-optic transducer in thin film lithium niobate, a material platform that provides a strong nonlinearity and low optical loss. On-chip efficiencies over .7% and with a bandwidth larger than 100MHz is demonstrated. Finally, we describe how efficiencies exceeding 10% can be achieved and discuss the potential of our transducer to be interfaced with commercially available superconducting qubits.