We perform two-colour pump probe experiments on metals and superconductors using synchronized 10-fs pulses generated by optical parametric amplifiers, tunable from the visible to the near-infrared, mapping with unprecedented detail the energy equilibration dynamics of the free electron gas. In gold films we observe dramatic changes of the differential reflectivity spectrum on the 100-fs timescale, corresponding to the establishment of the thermal electron distribution, with dynamics dictated by excess energy. In high-Tc cuprate superconductors we observe fast electron relaxation, attributed to a strong electron-phonon coupling which may play a role in the superconductivity mechanism.

Date Published: 21 February 2011
PDF: 7 pages
Proc. SPIE 7937, Ultrafast Phenomena in Semiconductors and Nanostructure Materials XV, 79371P (21 February 2011); doi: 10.1117/12.876856

Published in SPIE Proceedings Vol. 7937:
Ultrafast Phenomena in Semiconductors and Nanostructure Materials XV
Kong-Thon Tsen; Jin-Joo Song; Markus Betz; Abdulhakem Y. Elezzabi, Editor(s)