The concept of antimatter having negative mass is not accurate. Antimatter particles have the same mass as their corresponding matter particles, but they possess opposite charge. For example, an antielectron (positron) has the same mass as an electron but carries a positive charge instead of a negative charge.
Regarding the use of antimatter in warp drives or creating traversable wormholes, it's important to note that these concepts are purely speculative and fall into the realm of science fiction. While the theoretical physics of warp drives and wormholes has been explored, there are significant challenges and unknowns associated with these ideas.
In theoretical physics, the concept of negative mass or exotic matter has been proposed as a potential ingredient for hypothetical warp drives or wormholes. Such exotic matter would possess properties that go beyond the characteristics of known matter and would have negative energy density or negative pressure. However, the existence and properties of such exotic matter remain purely hypothetical and have not been observed or created in experiments.
It's essential to distinguish between scientific theories and the imaginative use of concepts in science fiction. While antimatter is a real phenomenon studied in particle physics, its properties and applications are governed by the laws of physics as we currently understand them, and they do not include the notion of negative mass or the ability to create warp drives or traversable wormholes.