Artificial atom

The term Artificial atom is commonly used to describe objects that have bound, discrete electronic states, as is the case with naturally occurring atoms. Semiconductor quantum dots are the most common example of artificial atoms.

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See also

• Programmable matter

Artificial atoms, or quantum dots, are really made up of more than one atom, but are like single atoms in one important way: when you provide the right amount (or quanta) of energy, they will give off coloured light.

When you combine a bunch of atoms to make a quantum dot (or artificial atom), it is still small enough for these quantum rules to stick. When you brighten a quantum dot with the right amount of energy, just like an atom, it will absorb that energy and then give off photons of only particular wavelengths. The wavelengths are determined by the size of the dot, which depends on the number of atoms that make up the dot. By controlling the number of atoms in the dots, an “artificial periodic table,” is made.

Artificial atoms are used to create lasers or to amplify light. Quantum dots can give off desired colors of light when they are exposed to electrical currents in a process that is similar to that at play in an LED. The current is a flow of negatively charged electrons going one way and holes flowing in the opposite direction. When the electrons meet the holes, they give off a photon. When quantum dots are properly added to a material, they can concentrate the flow of electrons and holes much like the drain in a shower. Artificial atom lasers and amplifiers have been made to improve how we use light in computer chips.