Implementation of a Quantum Addressable Router Using Superconducting Qubits
Connie Miao, Sébastien Leger, Ziqian Li, Gideon Lee, Liang Jiang, David Schuster · PRX Quantum · 2025
The implementation of a quantum router capable of performing both quantum signal routing and quantum addressing (a Q 2 -router) represents a key step toward building quantum networks and quantum random access memories. We realize a Q 2 -router that uses fixed-frequency transmon qubits to implement a routing protocol based on two native controlled- i gates. These gates leverage a large Z Z interaction to selectively route information according to a quantum address. We find an estimated average routing fidelity of 95.3 % , with errors arising primarily from decoherence or state preparation and measurement. We present a comprehensive calibration and characterization of both the c- i gates and the overall routing protocol through randomized benchmarking techniques and state tomography.