Attosecond laser provides first 'movie' of fast electrons jumping band-gap of semiconductor
The entire semiconductor industry, not to mention Silicon Valley, is built on the propensity of electrons in silicon to get kicked out of their atomic shells and become free. These mobile electrons are routed and switched though transistors, carrying the digital information that characterizes our age.
An international team of physicists and chemists based at the University of California, Berkeley, has for the first time taken snapshots of this ephemeral event using attosecond pulses of soft x-ray light lasting only a few billionths of a billionth of a second.
While earlier femtosecond lasers were unable to resolve the jump from the valence shell of the silicon atom across the band-gap into the conduction electron region, the new experiments now show that this transition takes less than 450 attoseconds.
"Though this excitation step is too fast for traditional experiments, our novel technique allowed us to record individual snapshots that can be composed into a 'movie' revealing the timing sequence of the process," explains Stephen Leone, UC Berkeley professor of chemistry and physics.
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http://phys.org/news/2014-12-attosecond-laser-movie-fast-electrons.html
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