Implementation of a Quantum Private Query Using Single-Photon Transistors

We propose a quantum-mechanical device consisting of transmon qubits connected to single-photon transmission lines that can be used to perform a boolean quantum private query on a database. Using numerical simulations verified by analytical calculations we analyse the dynamics of the query process in the proposed system by calculating the reflection and transmission probabilities of the photons encoding the questions. We show that the proposed device, which consists of experimentally available components, is capable of performing a quantum private query with high reliability and may form the basic building block of a lager-scale private search engine.