A metric unit of electrical current representing 10^-18 amperes, denoted by the symbol aA. This scale of measurement is equivalent to just a few electrons flowing past a point per second. Physicists and specialized electronics engineers use it when measuring microscopic leakage currents in advanced semiconductor devices or the output of highly sensitive single-electron transistors.
Heard on the job
The new electrometer can resolve currents down to a few attoamperes before thermal noise swamps the signal.