How quantum torpedoes exactly work

[Picard]

Do we have ANY canon info on workings of quantum torpedoes besides their name (which may or may not imply gravitational distortion)?

[Mr. Oragahn]

Perhaps they have increase the yields by managing to annihilate matter with even more proficiency than usual photon torpedoes? We know that during TNG, they'd be able to improve the yields, but possibly by a little. Assuming that there's been a waste in the amount of antimatter that reacted with matter, the UFP's quest in greater yields would have been to find a way to get as much of their antimatter to react as possible. Besides, the problem being vast, the particles generated by those explosions are multiple, and a lot can quickly be largely useless (notably the huge amount of neutrinos).
Quantum torpedoes would be a major advance in improving the reaction. Now, have black holes ever been related to them? Short lived small blackholes would make for fantastic weapons and would surely "digest" a lot of matter presented to them. Now exploiting the particles they'd release would be a tricky part.
Then again, it may have nothing to do with yields and be related to a multi-step mechanism that focuses particles in a more efficient way as to improve the penetration of forcefields. Technically, the yields would be considered greater due to a higher amount of particles actually doing something useful.
Even during TNG, they still hadn't mastered partially focused blasts until a certain point.

[Khas]

The only places that give info on how quantum torpedoes work are non-canon sources, like technical manuals. They say that quantum torpedoes use zero-point energy, or void energy. The energy of space-time itself.

[Lucky]

Do we have ANY canon info on workings of quantum torpedoes besides their name (which may or may not imply gravitational distortion)?

The simple answer is we don't know exactly how any weapon works in Star Trek because they tend to use physics we have yet to understand, but here goes.

Enterprise: Regeneration
DRAKE: Transmit your findings to Starfleet. Maybe they'll find a match in their database.
MONINGER: Right away.
ROONEY: Sir, I've run every test in the book. I still can't identify this alloy.
DRAKE: What about this?
ROONEY: I thought it was simple thermal damage until I found signs of antimatter residue.
DRAKE: Maybe their warp drive overloaded.
ROONEY: That could explain why there's not much debris. I did find some carbon traces.
DRAKE: Could you date them?
ROONEY: This debris has been here for about a hundred years.


Deep Space:9 To The Death
WEYOUN: The central structure is composed of solid neutronium. Even a direct hit from a quantum torpedo wouldn't necessarily destroy our objective.


Deep Space Nine: For The Uniform
WORF: Check the status of torpedoes three and four. We have an energy variance reading on the plasma warheads. Transfer power

Like I said we have no real idea as to how Quantum Torpedos work. We have seen Romulan Plasma torpedos that caused damage by crushing the target somehow, but then why call them quantum torpedos if they are simply plasma torpedos?

_____
Feel free to try to find more. I was just skimming the Memory Alpha page, and only checked about three of the listed sources.
http://en.memory-alpha.org/wiki/Quantum_torpedo

[Picard]

What are chances that quantum torpedoes are similar to H-bombs, in that they use photon torpedoes as a trigger for some kind of reaction?

As for my black hole idea, we do know that Romulans use black holes to power their ships. What do we know about that system?

[Mr. Oragahn]

They do call quantum torpedoes "plasma warheads" at some point, or is it another weapon type?

[Lucky]

They do call quantum torpedoes "plasma warheads" at some point, or is it another weapon type?

Photon and Photonic Torpedos have an antimatter warhead, but we don't know exactly how they actually cause damage. The Visual effects are often odd.

Quantum Torpedos have Plasma warheads, but we don't know exactly how they actually cause damage. The Visual effects are often odd.
They seem to have been developed as an anti-borg weapon.

Gravimetric Torpedos have a gravimetric warhead, and do something with gravity. You can apparently turn proto stars of a certain type into a wormhole with them, or close hole that leads to fluidic space.
They are not used as anti-ship weapons for some reason.