Exploring NbRe for superconducting microstrip single photon detectors: Fabrication and resistance behaviour

The superconducting nanostrip single photon detectors based on NbN exhibit unmatched performance at 1550 nm compared to the InGaAs single photon avalanche photodiodes at the same wavelength. However, they still have limitations in terms of active area and maximum detectable wavelength. Recently, single photon detectors based on superconducting microstrip in new materials have been very promising, as they could cover large areas and detect photons even in the mid infrared, extending the possibilities of use of this category of devices. The experiments point out that the role of vortices is crucial, accrediting the vortex-assisted detection mechanisms. According to the latter, a free vortex may be induced by photon absorption or appear as a result of a fluctuation and can give rise to a normal domain, responsible of a voltage pulse recording. Therefore, it is important to study the devices physical characteristics related to the vortices and their evidence in the material. In this work, we present the fabrication and the study of microstrips based on NbRe. We studied the resistance behaviour as the temperature decreases in order to investigate its superconducting properties according to the theoretical models based on the presence of vortices.