Superconducting nanowire single-photon detectors (SNSPDs) based on ultra-thin films have become the preferred technology for applications that require high efficiency single-photon detectors with high speed, high timing resolution, and low dark count rates at near-infrared wavelengths. Since demonstration of the first SNSPD using NbN thin films, an increasingly larger number of materials are being explored. We investigate amorphous thin film alloys of MoSi, MoGe, and WRe with the goal of optimizing SNSPDs for higher operating temperature, high efficiency and high speed. To explore material adequacy for SNSPDs, we have measured superconducting transition temperature (Tc) as a function of film thickness and sheet resistance, as well as critical current densities. In this paper we present our results comparing these materials to WSi, another amorphous material widely used for SNSPD devices.

In this contribution, we report progress in the preparation of superconducting materials made by Spark Plasma Sintering (SPS). On the one hand, the fabrication process was optimized in order to improve the texturing of Bi2Ca2Sr2CuO8 superconductor ceramics. The new process is referred to as “Spark Plasma Texturing” (SPT). During SPT, the bulk material is free to deform itself. As a result, an inter-grain preferential crystallographic orientation is generated, while materials processed by conventional SPS are usually quasi-isotropic. The crystallographic orientation causes a strong anisotropy in the magnetic properties of the Bi2Ca2Sr2CuO8 bulk.

On the other hand, superconducting MgB2 discs were consolidated using the rapid SPS process. MgB2 has not been yet been seriously considered as a superconductor that could be used for magnetic levitation. Here we present trapped field measurements as a function of the distance to the superconductor and field cooled levitation force measurements that suggests that it presents interesting characteristics for this application.