Performance of superconducting nanowire single photon detectors in strong magnetic fields*

Superconducting nanowire single photon detectors (SNSPD) have found applications in many fields, including nanophotonics, quantum communication and computing. There is potential in applications in high energy physics, but operation in high magnetic fields is required.
We study the performance of SNSPDs in high magnetic fields by implementing superconducting type-II materials with high upper critical fields and critical currents. Using the recently developed ion-beam assisted sputtering method[1], we fabricate Niobium Nitride SNSPDs on non-epitaxial substrates using a two-step process, and perform optoelectronic characterization across a wide range of magnetic fields. We demonstrate performance with zero dark counts and saturated internal quantum efficiency in fields of up to 8 T for visible wavelength photons with no need for changes to the common meander geometry[2].

[1] doi:10.1063/1.5031904
[2] arXiv:1907.13059