How to Make Lead look like Gold: Quantum Tracking Control

Recently, we theoretically unveiled an unexplored flexibility of nonlinear optics that a shaped laser pulse can drive a quantum system to emit light as if it were an arbitrary different system. This realizes an aspect of the alchemist's dream to make different elements look alike, albeit for the duration of a laser pulse. To understand this methodology, we need to define what "looking alike" means. One visually perceives a physical system due to a difference between light before (i.e., the optical input) and after (i.e., the optical response) interacting with the system of interest. Thus, to make two different systems look alike is equivalent to be able to match their optical responses. This finding has received broad public coverage in such scientific outlets as Physics, PhysicsWorld, Nature Materials, Quanta Magazine, Wired, etc