The Incredible Power of Quantum Memory

The original version of this story appeared in Quanta Magazine. It's not easy to study quantum systems--collections of particles that follow the counterintuitive rules of quantum mechanics. Heisenberg's uncertainty principle, a cornerstone of quantum theory, says it's impossible to simultaneously measure a particle's exact position and its speed--pretty important information for understanding what's going on. In order to study, say, a particular collection of electrons, researchers have to be clever about it. They might take a box of electrons, poke at it in various ways, then take a snapshot of what it looks like at the end.