It doesn't require any exotic tech, it requires achieving certain critical energy densities and profiles in the anti-armor weapon. It has been known for some time what these numbers were, but achieving them reliably is very hard. From a physics standpoint, normal molecular materials aren't all that tough. I don't believe they've ever been able to achieve this with a conventional gun-type device (not enough velocity) or usably with a shaped-charge explosive technology (which is too fragile functionally anyway).
The current technology platform of choice which can meet or exceed these limits reliably, which is showing up in a half-dozen forms in soon-to-be-deployed weapon systems, is "hyper-kinetic missile" technology. I am familiar with this class of weapons technology, and would point out that building them often requires some pretty exotic materials, as they themselves operate pretty close to the physical limits of what you can do with normal materials.