Superconducting nanostructures can be used to detect single photons. Here we propose to use electron-beam-induced deposition (EBID) of a superconducting tungsten-carbon alloy to create nanowires...Show moreSuperconducting nanostructures can be used to detect single photons. Here we propose to use electron-beam-induced deposition (EBID) of a superconducting tungsten-carbon alloy to create nanowires that can be used as a transition edge sensor (TES). Determining if these EBID-written nanowires can be used as an efficient TES requires an experimental characterization of its electrothermal properties. We demonstrate two key experiments to characterize a TES and introduce a numerical model to describe a TES with a nanofabricated constriction as a proof-of-concept. We characterize the low frequency impedance of a PTC thermistor and determine its electrothermal properties. We find a thermal conductance $G = 5.1 \pm 0.2 \text{ \textmu W/K}$ and a heat capacity $C = 0.48 \pm 0.03 \text{ \textmu J/K}$ and discuss how to extend these measurements to superconducting nanowires. A remotely controlled experiment is performed on NbTiN nanowires with a nanofabricated constriction. From the measured IV curves we determine the Joule heating and local temperature of the wire from an adapted Skocpol-Beasley-Tinkham model for a resistive transition. This model is valid for low values of the wire resistance. Together, these experiments and the model provide necessary infrastructure to characterize the electrothermal properties of EBID-written nanowires in the near future.Show less
