So it seems that the Nuclear Handgun, Powergun and Absorbic Bomb have all been busted, but this one might be more interesting, Larry Niven's Wunderland Treatymaker.
Description of how the weapon (apparently) works:
"The Wunderland Treatymaker was used only once. It was a gigantic version of what is commonly a mining tool: a disintegrator that fires a beam to suppress the charge on the electron. Where a disintegrator beam falls, solid matter is rendered suddenly and violently positive. It tears itself into a fog of monatomic particles.
Wunderland built, and transported into the Warhead system, an enormous disintegrator firing in parallel with a similar beam to suppress the charge on the proton."
When used, it could form a big gorge on a planet.
I was wondering if there are actual particle beams that can perform something like this. It needs not have this much destructive power, but at least work the way it was supposed to, to disintegrate materials. Assume that there is all the money needed for the particle beams.