The highest frequency of ac current?

[alikim]

I heard about a research where ac current is generared in metal covered nanotubes exposed to visible light, the same way as it does in receiving tv antennas.

Isn't there a limit to how quickly electrons can accelerate on a metal surface (because of inertia and maybe some extra factors) to actually have ac current? And wouldn't that be way lower than frequencies of the visible light?

Thank you!

 

[Jeff Rosenbury]

Accelerating electrons emit photons. Similarly, electrons that absorb photons accelerate. Since high energy gamma rays do this, the limit you seem to be looking for is in keeping the electrons in the metal. So what you seem to be asking is, what is the work function?