Design And Implementation Of Superconducting Nanowire Pulse Current Amplification And Readout Circuit

Superconducting nanowire single photon detectors(SNSPD)show superior performance and are key elements in light detection and ranging(Li DAR),deep space communication,long haul quantum imaging and many other defense and military applications.Large scale SNSPD arrays require a digital readout circuit to multiplexing each pixel.Due to the low temperature environment and weak output signal from detectors,the digital circuit has to be low power dissipation and have a high sensitivity.Superconducting nanowire cryotrons are novel detectors,which are energy efficient,high integration scalability,fast switching speed,suitable for reading and digitizing SNSPD arrays.We demonstrate a nTron amplifier with T-interface,which can amplify and readout the SNSPD pulses.This research shows a new possibility for the readout methods of large scale SNSPD arrays.This paper summarizes the research methods,implementation details,and results during the period of graduate study.The content includes the interfacing circuit between the SNSPD and nTron amplifier,test of the amplification and isolation,design,fabrication and characterization of the nTron and SNSPD,measurement setup,test protocol,and final results.In the end,we analyze the data and conclude that all the targets have been achieved.