Disentangling Complex Current Pathways in Metallic Nanostructures by Terahertz Spectroscopy

We demonstrate a sensitive contactless characterization method based on terahertz (THz) time-domain spectroscopy to analyze the current pathways in nano-metallic devices. Our analysis of the THz conductivity spectra of a nano-metallic Ru/Co bilayer, supported by a resistor-network model, allows for the determination of the complex-valued electronic transparency coefficients both of the metallic bilayer and the internal nanointerface. Hence, the contributions of the internal current pathways and the current splitting at the interface have been quantified.