Bose-Einstein Condensate

Definition: A Bose-Einstein condensate is a rare state (or phase) of matter in which a large percentage of bosons collapse into their lowest quantum state, allowing quantum effects to be observed on a macroscopic scale. The bosons collapse into this state in circumstances of extremely low temperature, near the value of absolute zero.

Satyendra Nath Bose developed statistical methods, later utilized by Albert Einstein, to describe the behavior of massless photons and massive atoms, as well as other bosons.

This "Bose-Einstein statistics" described the behavior of a "Bose gas" composed of uniform particles of integer spin (i.e. bosons). When cooled to extremely low temperatures, Bose-Einstein statistics predicts that the particles in a Bose gas will collapse into their lowest accessible quantum state, creating a new form of matter, which is called a superfluid. This is a specific form of condensation which has special properties.

These condensates were observed in liquid helium-4 during the 1930s, and subsequent research led to a variety of other Bose-Einstein condensate discoveries. Notably, the BCS theory of superconducitivity predicted that fermions could join together to form Cooper pairs that acted like bosons, and those Cooper pairs would exhibit properties similar to a Bose-Einstein condensate. This is what led to the discovery of a superfluid state of liquid helium-3, ultimately awarded the 1996 Nobel Prize in Physics.

Bose-Einstein condensates, in their purest forms, experimentally observed by Eric Cornell & Carl Wieman at the University of Colorado at Boulder in 1995, for which they received the Nobel prize. (Read more about their 2001 Nobel Prize in Physics.)

Also Known As: superfluid