Intrinsically-limited timing jitter in molybdenum silicide superconducting nanowire single-photon detectors

Abstract

Recent progress in the development of superconducting nanowire single-photon detectors (SNSPDs) has delivered excellent performances, and has had a great impact on a range of research fields. The timing jitter, which denotes the temporal resolution of the detection, is a crucial parameter for many applications. Despite extensive work since their apparition, the lowest jitter achievable with SNSPDs is still not clear, and the origin of the intrinsic limits is not fully understood. Understanding its intrinsic behaviour and limits is a mandatory step toward improvements. Here, we report our experimental study on the intrinsically-limited timing jitter in molybdenum silicide (MoSi) SNSPDs. We show that to reach intrinsic jitter, several detector properties such as the latching current and the kinetic inductance of the devices have to be understood. The dependence on the nanowire cross-section and the energy dependence of the intrinsic jitter are exhibited, and the origin of the limits are explicited. System timing jitter of 6.0 ps at 532 nm and 10.6 ps at 1550 nm photon wavelength have been obtained.Since their first demonstration 1 , superconducting nanowire single-photon detectors (SNSPDs) have emerged as a key technology for optical quantum information processing 2 . Their low dark count rate, fast response time, small jitter, and high efficiency favours their use in various demanding quantum optics applications such as quantum key distribution 3 , quantum networking 4 , device-independent quantum information processing 5 , deep-space optical communication 6 , IR-imaging 7,8 , and integration in photonic circuits 9-11 .One advance in the SNSPD field has been the introduction of amorphous superconductors such as tungsten silicide (WSi) 12 and molybdenum silicide (MoSi) [13][14][15][16] . SNSPDs based on these materials currently have the highest reported system detection efficiencies (SDE) (93% for WSi 12 ). Their amorphous properties makes them materials of choice for applications where the film quality and yield are crucial, such as multi-mode coupled SNSPDs, or large arrays 17 .

Satellite-based quantum information networks: use cases, architecture, and roadmap

“…To further reduce noise, it is possible to add narrow-bandwidth filters as close as possible to the detector so as to achieve noise rates lower than 1 count per second. The other interesting characteristics are the time jitter which is of the order of 20 ps, and the recovery time of the order of 100 ns to return to 90% of nominal efficiency 72,73 . Note that this recovery time is due to the electrical impedance of the wire, which slows the return of current to the superconductor.…”

16-Element Superconducting Nanowire Single-Photon Detector for Gigahertz Counting at 1550-nm

“…Superconducting nanowire single-photon detectors (SNSPDs) have proliferated the optics community in recent years due to their unique combination of high detection efficiency (≥ 98%) 1 , extremely low dark counts (< 1/s for UV 2 , < 100/s commercially avilable at 1550 nm), broad spectral response from UV to mid-infrared [2][3][4] , precise timing accuracy (<4.3 ps FWHM intrinsic timing jitter at 1550 nm for NbN nanowires, and <10.6 ps FWHM intrinsic timing jitter at 1550 nm for MoSi) 5,6 , and recent discovery of true photon number resolving capacity 7,8 . Diverse fields as quantum optics [9][10][11][12] , spectroscopy 13 , and free-space optical communications 14,15 have leveraged SNSPDs with great success and driven the rise of commercially available SNSPD systems.…”

Operation of parallel SNSPDs at high detection rates

“…This relatively high jitter could be a consequence of the lower output signal of our devices compared to single meander SNSPDs. Indeed the signal over noise ratio is an important contribution of the total jitter of the system 8,30 . However, it is interesting to note that the geometric contribution to the jitter per nanowire is expected to be smaller here due to the shorter nanowires required in our designs 7,31 , which perhaps contribute positively to our jitter value.…”