Drexel University Physics Colloquium - 18th Annual Kaczmarczik Lecture - NOTE TIME

ABSTRACT: In 1935, Erwin Schrodinger, 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 might be useful for computation. 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 problems that are intractable on normal computers. So far, scientists have constructed quantum computers composed of only a few bits, but with advances in technology, we believe a useful device may someday become a reality.