Extended Data Fig. 3: Relative latency and jitter measurements with WSi.

a, The PCR curves and b, corresponding relative latency between 775 nm and 1550 nm light detections for a 160 nm-wide WSi detector with the same design as the NbN detectors. The film thickness was 3.5 nm giving a critical temperature of 3.4 K and a room temperature sheet resistance of 422 Ω□^-1. The depairing current (I_dep) was estimated to be 14.1 μA by fabricating resonator devices, just as for NbN devices. A switching current of about 11.5 μA was achieved with the low jitter device, which is >0.8I_dep. This means that the WSi and NbN devices are similar in terms of uniformity, since they achieve similar fractions of the depairing current. The relative latency increases from 12 ps to 80 ps when decreasing bias current from 0.78I_dep to 0.43I_dep, while the 120 nm-wide NbN device resulted in approximately 6 ps and 23 ps at comparable fractions of the depairing current. Due to the larger intrinsic latency in the WSi device, the resulting jitter is also larger as illustrated in c. At a bias current of 11.0 μA the jitter is 7.7 ps and 16.2 ps for 775 nm and 1550 nm light, respectively, while for the 120 nm NbN device the corresponding jitter is 4.5 ps (775 nm) and 7.7 ps (1550 nm) at the same fraction of the depairing current.