BoseEinsteinkondensater

Bose-Einstein condensate, or BEC, is a state of matter formed when bosons are cooled to temperatures near absolute zero. At such low temperatures a large fraction of the particles occupy the lowest quantum state, and the individual particle wavefunctions merge into one coherent macroscopic wavefunction. This results in collective quantum phenomena that can be observed on a macroscopic scale.

Predicted by Satyendra Nath Bose and Albert Einstein in the 1920s, the condensate was first created in 1995 in dilute atomic gases by Eric Cornell and Carl Wieman (University of Colorado) and Wolfgang Ketterle (MIT). The achievement earned the Nobel Prize in Physics in 2001.

In a BEC the system exhibits long-range phase coherence and features characteristic of superfluidity, such as frictionless flow and quantized vortices. The condensate is typically formed in ultrahigh vacuum and at temperatures of a few hundred nanokelvin, using laser cooling and evaporative cooling in magnetic or optical traps. Common experimental atoms include rubidium-87 and sodium-23.

Significance: BEC provides a versatile platform for studying quantum many-body physics, quantum simulations of complex materials, and precision measurements. It also enables advances in atom interferometry and fundamental tests of quantum mechanics at macroscopic scales. Researchers continue to explore interactions, dimensionality, and dynamics in condensates, as well as applications in quantum technologies.