Аннотация:Superconducting Josephson structures play a significant role in quantum-state engineering. Achieving high-fidelity quantum state measurements in superconducting Josephson structures requires ultra-low noise environments and robust signal purification techniques. Here, we present our advanced low-noise signal measurement system designed for dilution refrigerators, integrating multi-stage cryogenic filtering and electromagnetic shielding strategies to suppress noise sources across a broad frequency spectrum. We demonstrate the effectiveness of low-pass RC filters, silver-epoxy microwave absorbers, and optimized ground isolation to achieve an unprecedented noise reduction, enabling sub-nanoampere switching current distribution measurements superior to commerical systems at mK temperatures. Our system is optimized for precision studies of SIS, SFS, and SNS Josephson junctions with low critical currents. This approach establishes a reliable framework for next-generation quantum electronic experiments, ensuring that observed switching phenomena are governed by intrinsic device physics rather than environmental perturbations.
