Speaker: David Wineland (National Institute of Standards and Technology (NIST) and 2012 Nobel Laureate in Physics)

In 1935, Erwin Schrödinger, one of the inventors of quantum mechanics, illustrated his discomfort with the theory by pointing out that its extension to the macroscopic world could lead to bizarre situations such as a cat being simultaneously alive and dead, a so-called superposition state. Today, we can create similar situations on a small scale, such as putting an atom in a “bowl” and placing it on the left and right sides of the bowl simultaneously.

Superpositions are potentially useful for information processing. For example, two energy levels in an atom, labeled "0" and "1," can be used to store information like the bits in our laptops. However, as in the atom/bowl experiment, we can arrange the quantum bit to be in a superposition, thereby storing both states of the bit simultaneously. This property leads to a memory and processing capacity that increases exponentially with the number of bits. This and a related property called “entanglement” would enable a quantum computer to efficiently solve certain problems that are intractable on normal computers.

Research on precise control of quantum systems occurs in many labs throughout the world, for fundamental research, new measurement techniques, and more recently for quantum information processing. I will briefly describe experiments on quantum state manipulation and atomic clocks that employ trapped atomic ions. This talk is, in part, the “story” of my involvement in these topics that I presented at the 2012 Nobel Prize ceremonies.