Last year I think it was, someone suggested that the USA could soon use a “Z-pinch” device to create the needed energy gradients to allow a spacecraft to exceed the speed of light.
Aside from the frankly terrifying thought of interstellar expansion being sponsored by Starbucks and Disney, it’s a nice idea. But you still need a power source.
In Star Trek the whole ship’s powered by a massive anti-matter reactor. Oh, it has several small fusion power sources dotted around the ship, including some dedicated for the Impulse Engines if I remember rightly. Yet the anti-matter plant, the “warp core”, runs 24/7. Before this gets too long-winded, I have trouble with how much power the ship requires. Okay, the warp drive bends space-time to extreme degrees, the transporters are essentially managing very controlled atomic annihilation and reconstruction, the replicators also do the matter-energy conversion as does the holodeck to some degree. It’s quite frivolous, but expected in an apparently “free energy” future.
Within our lifetimes though, the economy of having a sustained annihilation reaction seems questionable. However if I understand it, the Z-pinch concept is to create a sudden burst of energy, that would somehow flip the vessel across great distances. To be able to do that continually would need something like the Trek reactor. But since the Pinch seems to be a one-shot concept, you’d only need a single burst of energy.
Antimatter is a terrible thing, and controlling such a fundamentally unstable substance would be very tricky. However it does go bang very nicely. So if you need a sudden intense burst of power, such as for energising a Z-pinch device (possibly explosively in a similar method to an EMP device*) then a bottle of antimatter may be just the battery you require.
I recall hearing that the interstellar engine on Serenity, in Joss Whedon’s Firefly, was planned to be the sort of drive that wasn’t casually used, but that everyone held on for dear life and hoped it wouldn’t explode when turned on.
An annihilation-powered-Z-pinch would probably be a similar, terrifying experience.
* I wonder if any sci-fi writers have yet considered the use of a one-shot disposable FTL drive?