Thursday, 4 June 2020

Bose Einstein Condensate- our fifth state of matter

We all were well studied about four states of matter - solid, liquid, gas and plasma. There is also fifth state of matter which is much mysterious and is called Bose Einstein Condensate. It is a state of matter in which atoms and subatomic particles are cooled to absolute zero temperature (0K). At such low temperature, they have no free energy to do any random movements. At this point, they clump together and the whole group starts behaving like as though it were a single particle. This form of matter was discovered by Albert Einstein in 1924 on the basis of the formulations derived by the Indian physicist Satyendra Nath Bose.
To make bose Einstein condensate, scientists used atoms of rubidium. Then cooled them with laser, this takes away all their energies by imposing radiative pressure. After that, cooling of atoms starts which was further supported by evaporative cooling. In 1990s Cornell and Wieman succeeded in merging together 2000 individual atoms and called it superatom. Superatom is nothing but a large condensate enough to be viewed by a microscope also.

BEC theory has traced back to 1924, when Bose observed that there are two classes behave differently. Fermions tend to avoid each other and each electron in a group occupies different quantum states. Whereas there are bosons also in which can share number of particles share single quantum state. Einstein extended this work and named such particles as ‘bosonic atoms’ which have even spins and they collapse together to exist in single quantum state at absolute zero temperature. At that time there was no method to attain such low temperature, that’s why we waited so long until 1990s.
BEC is related to two interesting phenomena: superconductivity and superfluidity. Superconductivity- in which electrons move through material with zero electrical resistance and superfluidity- in which helium isotopes forms liquid that offers zero friction.
APPLICATIONS
  •  Can be used for the detection of gravitational field intensity.
  • It can be combined with atomic lasers to create high precision nano-structures.
  • It is used in the study of cosmological phenomena by undergoing various simulations.
  • Applications in superconductivity and superfluidity.
  • It deepens the knowledge of quantum mechanics.

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