Demonstration of digital readout circuit for superconducting nanowire single photon detector

Abstract

We demonstrate the transfer of single photon triggered electrical pulses from a superconducting nanowire single photon detector (SNSPD) to a single flux quantum (SFQ) pulse. We describe design and test of a digital SFQ based SNSPD readout circuit and demonstrate its correct operation. Both circuits (SNSPD and SFQ) operate under the same cryogenic conditions and are directly connected by wire bonds. A future integration of the present multi-chip configuration seems feasible because both fabrication process and materials are very similar. In contrast to commonly used semiconductor amplifiers, SFQ circuits combine very low power dissipation (a few microwatts) with very high operation speed, thus enabling count-rates of several gigahertz. The SFQ interface circuit simplifies the SNSPD readout and enables large numbers of detectors for future compact multi-pixel systems with single photon counting resolution. The demonstrated circuit has great potential for scaling the present interface solution to 1,000 detectors by using a single SFQ chip.

Experimental Analysis of the Bias Dependent Sensitivity of a Josephson Comparator

“…For each particular clock frequency, we obtain a minimum possible gray zone. This result is in very good agreement to experimental results for a comparator implemented in a detector readout circuit [11] realized in the same technology. By including parasitic inductances of the junction model, a realistic embedding of the comparator into other SFQ circuits we obtained a very good agreement between experimental results and circuit simulations.…”

Effect of Cherenkov radiation on the jitter of solitons in the driven underdamped Frenkel-Kontorova model

“…Soliton solutions of the FK model correspond to magnetic flux quanta that represent data bits in the circuits. In addition, a number of devices on the basis of superconducting circuits for field and current sensors [10,11] and readout systems for applications in optical communications, quantum cryptography, quantum-optical studies, and radio astronomy [12][13][14][15][16] have been proposed and tested.Digital technology requires the synchronization of events that correspond to operations with data bits. Since physical…”

Superconducting nanowire single-photon detector with integrated impedance-matching taper

“…using silicon germanium and gallium arsenide transistors. [13][14][15][16] Digital readout circuits built directly from superconducting electronics, such as nanocryotrons 17 and single flux quantum (SFQ) circuits, 18,19 have also been demonstrated. These integrated superconducting circuits are low-noise and scalable, but usually require additional biasing and suffer from leakage current and crosstalk.…”