A three-terminal semiconductor-superconductor transimpedance amplifier

The authors report an improved hybrid three-terminal transimpedance amplifier (TIA) with significant current gain. The TIA consists of a semiconductor diode configured for injection of electrons into a thin base electrode (<25 nm) superconductor-insulator-superconductor junction, whose response is read out by low-impedance superconductive electronics. An input dynamic impedance greater than 10/sup 11/ Omega , an output dynamic impedance of approximately 10/sup -3/ Omega a current gain of 20, and an effective input noise current less than 10/sup -14/ A/ square root Hz were achieved. The TIA was operated in a sensor test bed with an extrinsic silicon infrared (IR) detector and superconductive analog-to-digital (A/D) converter. This device permits matching state-of-the-art semiconductor IR detectors with superconductive A/D converters, enabling a fully digital cryogenic focal plane array sensor with high sensitivity and speed but reduced power consumption.<>