Abstract
The response of superconducting aluminum to electromagnetic radiation is investigated in broad frequency (45 MHz–40 GHz) and temperature ranges by measuring the complex conductivity. While the imaginary part probes the superfluid density (Cooper pairs), the real part monitors the opening of the superconducting energy gap and—most important here—the zero-frequency quasiparticle response. Here we observe the full temperature and frequency dependences of the coherence peak. Varying the mean-free path gives insight into the dynamics, scattering, and coherence effects of the quasiparticles in the superconducting state.
3 More- Received 21 May 2008
DOI:https://doi.org/10.1103/PhysRevB.77.214517
©2008 American Physical Society