Scott Aaronson on quantum supremacy, which was apparently achieved by Google in 2019.

A great lecture by the same Scott Aaronson on the mathematical foundations of quantum theory from a different perspective to what I have usually seen.

This is just one lecture from a whole course by Aaronson on quantum stuff (a physics course: Quantum Computing since Democritus) which is freely available on his site.

Andy Matuschak’s interesting experimental spaced recognition course in quantum computing.