Analysis Of Electrodynamics Behavior And Terahertz Optical Characteristics Of Superconducting Thin Film Systems
Keywords:
Superconducting thin films, THz spectroscopy, optical conductivity, London penetration depth, BCS theoryAbstract
This study presents a systematic analysis of the electrodynamics behavior and terahertz (THz) optical characteristics of superconducting thin film systems, including niobium nitride (NbN), tantalum nitride (TaN), yttrium barium copper oxide (YBCO), and zirconium nitride (ZrN). Applying THz frequency-domain spectroscopy as the primary analytical framework and leveraging verified experimental datasets from peer-reviewed sources (2011–2024), this paper examines complex optical conductivity σ̂(ω), London penetration depth λ(T), quasiparticle dynamics, and the BCS superconducting energy gap 2Δ across the 0.1–1.1 THz frequency range. Two objectives guide the study: characterizing the THz electrodynamics response across the superconducting transition and evaluating how film thickness, disorder, and material class modify this response. Findings confirm that weakly disordered NbN and TaN films conform to Mattis-Bardeen BCS predictions with gap ratios 2Δ(0)/kBTc ≈ 3.52, while YBCO manifests d-wave gap symmetry with markedly different THz optical signatures. ZrN films (18–48 nm) exhibit Tc values between 5.0 and 7.3 K with monotonic thickness dependence. These results carry direct implications for quantum sensing, superconducting single-photon detectors, and THz device engineering.
