Regensburg 2025 – scientific programme
Parts | Days | Selection | Search | Updates | Downloads | Help
TT: Fachverband Tiefe Temperaturen
TT 11: Superconductivity: Poster
TT 11.5: Poster
Monday, March 17, 2025, 15:00–18:00, P4
Terahertz investigations on superconducting nitride thin films — •Yayi Lin1, Frederik Bolle1, Janine Lorenz2, Marcello Guardascione2, Marc Neis2, Thomas J. Smart2, Martin Dressel1, Rami Barends2, Pavel Bushev2, F. Stefan Tautz2, Felix Lüpke2, and Marc Scheffler1 — 11. Physikalisches Institut, Universität Stuttgart, Stuttgart, Germany — 2Peter Grünberg Institut, Forschungszentrum Jülich, Jülich, Germany
In recent years, superconducting nitride thin films have garnered significant attention, for example for applications in quantum electronics. Due to the wide range of accessible kinetic inductance, high critical temperature, and correspondingly large energy gap, these materials are readily utilized in microwave resonators, low-temperature amplifiers, and quantum circuits.
We use terahertz (THz) spectroscopy to probe the electrodynamics of superconducting NbTiN (Tc > 10 K) and TiN (Tc > 3 K) thin films at frequencies below and above their superconducting energy gaps. We combine THz frequency-domain spectroscopy and THz time-domain spectroscopy to cover the frequency range from 100 GHz to 3 THz. We present key properties of several nitride thin films such as critical temperature (Tc), complex optical conductivity (σ), energy gap (2Δ), superfluid density (ns), and kinetic inductance (Lk). Of particular interest is the absolute value of the superconducting energy gap, which allows comparison with other spectroscopic techniques and predictions based on BCS theory.
Keywords: Disordered superconductors; THz spectroscopies; NbTiN; TiN; optical conductivity