Scientists measure speedy electrons in silicon

In semiconductors like silicon, electrons attached to atoms in the crystal lattice can be mobilized into the conduction band by light or voltage. scientists have taken snapshots of this very brief band-gap jump and timed it at 450 attoseconds. Attosecond lasers provide the shortest light pulses yet, allowing observation of nature's most short-lived events. Researchers have used these lasers for the first time to take snapshots of electrons jumping from silicon atoms into the conduction band of a semiconductor, the key event behind the transistor. They clocked the jump at 450 attoseconds and saw the rebound of the crystal lattice 60 femtoseconds later: a delay 120 times longer than the jump itself.