Mathematicians love a good puzzle. Even something as abstract as multiplying matrices (two-dimensional tables of numbers) can feel like a game when you try to find the most efficient way to do it.

A recent paper set the fastest record for multiplying two matrices. But it also marks the end of the line for a method researchers have relied on for decades to make improvements. For computer ...

Figure 1: Determination of charge density following optical excitation in a monocrystalline PbS film. Finally, the presence of large amounts of surface defects in quantum dots might provide an extra ...