Cooper Pair Breaking in Lead Measured by Pulsed Terahertz Spectroscopy
A technique for characterizing pulsed far-infrared radiation with a demonstrated resolution of approximately 100 fs is used to measure directly 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.
© 1993 IEEE
“Cooper pair breaking in lead measured by pulsed terahertz spectroscopy,” J. F. Federici, B. I. Greene, P. N. Saeta, D. R. Dykaar, F. Sharif, and R. C. Dynes, IEEE Trans. Appl Supercond. 3, 1461 (1993). doi: 10.1109/77.233620