NIST logo

Publication Citation: Identifying capacitive and inductive loss in lumped element superconducting hybrid titanium nitride/aluminum resonators

NIST Authors in Bold

Author(s): Martin P. Weides; Jeffrey S. Kline; Martin O. Sandberg; David P. Pappas;
Title: Identifying capacitive and inductive loss in lumped element superconducting hybrid titanium nitride/aluminum resonators
Published: June 09, 2012
Abstract: We present a method to systematically locate and extract capacitive and inductive losses in superconductingresonators at microwave frequencies by use of mixed-material, lumped element devices. In these devices, ultra-low loss titanium nitride was progressively replaced with aluminum in the inter-digitated capacitor and meandered inductor elements. By measuring the power dependent loss at 50 mK as the Al/TiN fraction in each element is increased, we find that at low electric field, i.e., in the single photon limit, the loss is two level system in nature and is correlated with the amount of Al capacitance rather than the Al inductance. In the high electric field limit, the remaining loss is linearly related to the product of the Al area times its inductance and is likely due to quasiparticles generated by stray IR radiation. At elevated temperature, additional loss is correlated with the amount of Al in the inductance, with a power independent TiN-Al interface loss term that exponentially decreases as the temperature is reduced. The TiN-Al interface loss is vanishingly small at the 50 mK base temperature.
Citation: Applied Physics Letters
Volume: 101
Issue: 2
Pages: 5 pp.
Research Areas: Condensed Matter Physics, Superconductivity
DOI: http://dx.doi.org/10.1063/1.4730389  (Note: May link to a non-U.S. Government webpage)
PDF version: PDF Document Click here to retrieve PDF version of paper (1MB)