First off, I would like to say that my highest level of physics education is an AP high school physics class. So if my knowledge is incomplete, misunderstood, or just plain wrong, please forgive me. On to the question. So I recently heard about the refinement of the Alcubierre drive(warp drive, essentially) to the extent where instead of requiring the mass energy of Jupiter, it would require the mass energy of Voyager. I don't remember the exact figure but I remember it being stated somewhere that it was the amount of energy the US uses in one year. The only flaw in the Alcubierre drive, however, is that it requires that figure to be in a negative energy density. I remember reading somewhere that negative energy densities do happen, however only in the quantum state. My question is this: How probable is it that exotic matter that would work for an Alcubierre drive would actually exist? Is it possible that Dark Matter/energy could fill this requirement if we managed to manipulate it a certain way? Lastly, is it even possible that it could be a simple element that would have to be created in a lab that would allow us to fulfill this negative energy problem? Any insights would be well appreciated!