Quantum sensors take the biggest roadblock for quantum computers—unwanted interference, or noise—and turn it into a strength. Noise wrecks quantum computers because the quantum states they use for computation are affected by the slightest disturbances from the environment. But quantum sensors use those disturbances to detect minuscule changes in magnetic and electric fields. Amanda Stein, the CEO of Quantum Catalyzer (Q-Cat), is working to find meaningful markets for sensors based on quantum def...