At present, there is no scientific evidence or widely accepted theoretical framework suggesting that time crystals or quantum computers can be used to build a time machine. The concept of time travel is highly speculative and remains within the realm of science fiction.
Time crystals are a recently discovered state of matter that exhibit an intriguing phenomenon called "time-translation symmetry breaking." They involve a form of organization and movement that repeats in time, but the applications and implications of time crystals are still being explored. Time crystals are a subject of active research, but their connection to time travel or building a time machine is purely speculative and unsupported by current scientific understanding.
Quantum computers, on the other hand, are powerful computational devices that utilize quantum mechanical principles to perform certain computations more efficiently than classical computers. While they have the potential to revolutionize various fields, including cryptography, optimization, and simulations, there is no established scientific basis to suggest that quantum computers could be used as a tool for time travel.
It is important to distinguish between the scientific concepts and theories that are grounded in rigorous research and the imaginative speculations found in science fiction. As of now, building a time machine using time crystals or quantum computers is purely speculative and falls outside the realm of scientific possibility based on our current understanding of physics.