We use a new technique of characterizing pulsed far-infrared radiation with a demonstrated resolution of ~100fs to directly measure Cooper pair breaking in superconducting lead. A 100-fs pulse of visible light is used to excite a thin-film lead sample while the Cooper pair density is optically probed using a pulse of broadband far-infrared radiation. Subsequent to the absorption of the visible pulse, a rapid (< 1 ps) change in the far-infrared optical transmission is observed, corresponding to the breaking of Cooper pairs. These results have implications for thin-film superconducting transmission lines carrying short electrical pulses.
All Science Journal Classification (ASJC) codes
- Electronic, Optical and Magnetic Materials
- Condensed Matter Physics
- Electrical and Electronic Engineering