Demonstration of Microwave Multiplexed Readout of DC-Biased Superconducting Nanowire Detectors

Abstract

Superconducting nanowires are widely used as sensitive single photon detectors with wide spectral coverage and high timing resolution. We describe a demonstration of an array of DC biased superconducting nanowire single photon detectors read out with a microwave multiplexing circuit. In this design, each individual nanowire is part of a resonant LC circuit where the inductance is dominated by the kinetic inductance of the nanowire. The circuit also contains two parallel plate capacitors, one of them is in parallel with the inductor and the other is coupled to a microwave transmission line which carries the signals to a cryogenic low noise amplifier. All of the nanowires are connected via resistors to a single DC bias line that enables the nanowires to be current biased close to their critical current. When a photon hits a nanowire it creates a normal hot spot which produces a voltage pulse across the LC circuit. This pulse rings down at the resonant frequency of the LC circuit over a time period that is fixed by the quality factor. We present measurements of an array of these devices and an evaluation of their performance in terms of frequency and time response.

Properties of a Nanowire Kinetic Inductance Detector Array

“…The device presented in this paper exploits the multiplexing capability of KIDs to build an array of SNSPDs. Recent work has demonstrated the operation of this array with 3 pixels connected [11]. Here we report on the progress of the device as a 12 pixel array.…”

Recent advances in superconducting nanowire single-photon detector technology for exoplanet transit spectroscopy in the mid-infrared

“…19 SNSPDs are compatible with frequency domain multiplexing schemes similar to MKID readout, and 16-pixel SNSPD arrays have been demonstrated with both dc and ac biasing schemes. 20,21 SNSPDs' high timing resolution and low velocity of propagation can be converted into position information by reading out the time difference between pulses leaving both ends of the device: the closer the position of the absorbed photon to one end of the nanowire, the longer the delay between when the pulse reaches the closer end of the nanowire and when it reaches the farther end of the nanowire. This time-of-flight information has been used to construct an imager with 590 effective pixels out of a single nanowire element.…”

Unconventional Applications of Superconducting Nanowire Single Photon Detectors

“…The tradeoff is in reduction of SNR of the detector (the voltage drop in inversely proportional to the number of pixels connected in parallel), but typical signals are on the order of a few mV, so this is not a fundamental problem unless the number of parallel pixels becomes too large. Lastly, the engineering problems associated with many-pixel readout are being focused on by many groups working on superconducting electronics and working arrays of as many as 64 pixels have existed for some time [ 63 , 64 , 65 , 66 ] and, coupled with various switching readout and multiplexing techniques [ 65 , 67 , 68 , 69 , 70 , 71 , 72 ], a kilopixel SNSPD array has been recently developed [ 73 ]. Specifically in the context of particle detection, the covered area can be further increased by increasing the dimensions wire itself—while this is generally not possible with photons, charged particles can create hotspots an order of magnitude larger (as will be discussed in Section 4 ).…”