Good overview. I think too
Good overview. I think too that the drag and therefore the thrust needed at supersonic speeds is not just linearly more than at lower speeds. A jetliner would have to have space for people, so it would be hard to make perfect in terms of aerodynamic efficiency at supersonic speeds. That means the thrust maker (electric motor) has to be pretty amazing, and I am not sure that without expanding hot gases, like from combustion fuels, it would be possible.