Fig. 4: Two-dimensional superconductivity in FeTe/CdTe films.
From: Superconductivity and suppressed monoclinic distortion in FeTe films enabled by higher-order epitaxy
a Temperature dependence of resistivity with different thickness t. The black and red arrows indicate the onset and zero-resistivity critical temperatures, Tc and Tc0, respectively, for the t = 10 nm sample. The inset shows t dependence of Tc and Tc0. b Temperature dependence of sheet resistivity of the t = 40 nm thin film on logarithmic (main panel) and linear (inset) scales at zero field. The red curve represents fitting result using Halperin-Nelson (HN) formula with TBKT = 5.8 K. c I-V curves in the log-log scale taken with 1-ms-pulsed currents. The measurements were performed at T = 2-10 K in 1 K increments, and additionally at 5.5 K and 15 K. The dashed lines represent linear fittings. The solid black and magenta lines show slopes for V ∝ I and V ∝ I3, respectively. The inset shows temperature dependence of α. The exponent crosses α = 3 at around TBKT = 5.8 K. d Polar angle θ dependence of Hc2. The red solid and cyan dashed lines represent the theoretical 2D Tinkham and 3D anisotropic mass models, respectively. The inset panel shows an expanded view around θ = 90∘. The inset cartoon illustrates the experimental configuration.
