For decades, the promise of quantum computing has tickled the neurons of drug-makers, spies, and tech CEOs. Such a machine, if perfected, would speed up drug discoveries, decode ciphers, and help AIs parse our digital data. This new brain hinges on the bendy concept of superposition, the idea that an object can be in two states at once—a coin spinning so fast, it's both heads and tails.

Conventional computer chips, whether in your phone or a supercomputer, hold transistors that process information as binary code: Everything is either a 0 or a 1. Quantum computers use qubits ( "cue-bits"), which can be both a 0 and a 1. The machines they inhabit can crack problems faster.