An artificial atom is an object that has bound, discrete electronic states, as is the case with naturally occurring atoms or molecules. Semiconductor quantum dots are the most common example of artificial atoms, and are analogies for real atoms.
In the form of quantum dots they are made up of tens to thousands of atoms. They are like single atoms in one important way: when you provide the right amount (or quanta) of energy, they will absorb that energy and may give it off as coloured light.
- Ashoori, RC (1996). "Electrons in artificial atoms". Nature 379 (6564): 413–419.