We report on a direct kinetic measurement of Cooper-pair breaking in superconducting lead. A 100-fs pulse of visible light was used to excite a thin-film lead sample, while the Cooper-pair density was optically probed using an ultrashort pulse of broadband far-infrared radiation. Subsequent to the absorption of the visible light, a rapid (ps) change in the far-infrared optical transmission was observed, corresponding to the breaking of Cooper pairs and the collapse of the superconducting gap.
© 1992 American Physical Society
“Direct picosecond measurement of photo-induced Cooper pair breaking in lead,” J. F. Federici, B. I. Greene, P. N. Saeta, D. R. Dykaar, F. Sharif, and R. C. Dynes, Phys. Rev. B 46, 11153 (1992).