What Is a Bose-Einstein Condensate?
Your elementary school teacher may have taught you that there are three states of matter: Solids, liquids and gases. The fourth state of matter is plasma, which occur at extremely hot temperatures. Recently, scientists have discovered the fifth sate of matter — the Bose-Einstein condensate.
A Bose–Einstein condensate (BEC) is a state of matter that exists in temperatures close to absolute zero. They are typically formed when bosons are cooled to extremely cold temperatures.
How Did We Discover the Bose-Einstein Condensate?
Albert Einstein first postulated the existence of this state of matter.
Satyendra Nath Bose then developed statistical methods to describe the behavior of these particles, which were later coined “bosons”. These methods were later implemented by Albert Einstein. Thus, the BEC was named to commemorate the contributions of Bose and Einstein.
What’s So Interesting about BECs?
BECs are intriguing because they display quantum behaviour on a macroscopic scale. For example, superfluidity has been observed in BECs. Superfluids have zero viscosity and zero friction when flowing across a surface. Keep in mind that these behaviors are guaranteed to occur in a BEC, but rather frequently observed in one. In other words, these behaviors are not direct consequences of a BEC, but are correlated with this peculiar state of matter.
Bosons
Bosons are elementary particles with an integer spin. They are indistinguishable from each other. That is, that if we have a system of two or bosons, we can not tell which boson is which.
Bosons are important in physics. The Higgs Boson gives rise to the phenomenon of mass. Photon are the force carrier of the electromagnetic field. The eight types of gluons force carriers that mediate the strong force. The neutral weak boson and the charged weak boson mediates the weak force. Thus, scientists postulate that the Higgs Boson also accounts for why gravity is much weaker than the other fundamental forces.
Producing a Bose-Einstein Condensates
The quest to produce a BEC was proven a herculean task. Nevertheless, scientists strived to turn theory into reality.
On 5 June 1995, the first BEC was produced by Eric Cornell and Carl Wieman at the University of Colorado. Shortly after, Wolfgang Ketterle at MIT produced a BEC with a gas of sodium atoms.
When bosons are cooled down, but it doesn’t form a lattice like a solid. Instead, the atoms fall into the same quantum states, thus leading them to be indistinguishable from one another. Atoms thus start obeying Bose-Einstein statistics.
These early studies pioneered the field of condensed matter physics.
