Josephson Junction Based Control Electronics for Superconducting Qubits

Superconducting qubit systems are controlled using a mix of continuous-wave AC, pulse-shaped AC, and DC signals. These signals are generated at room temperature and are then routed into a dilution refrigerator where they are attenuated and thermalized to appropriate levels for the qubit(s). In this work, we experimentally demonstrate the generation of control signals at 4K using Josephson junction-based circuits. These signals are then used to perform qubit energy level spectroscopy and digital control of a transmon qubit at temperatures below 0.1K. Josephson junction (JJ) based electronics can be used to produce low power consumption, self-calibrated, and reproducible digital and analog signals at cryogenic temperatures. All of these features may benefit future large-scale quantum information systems.