What happens to matter during Bose-Einstein condensation?

During Bose-Einstein condensation, matter undergoes a phase transition that occurs at extremely low temperatures, close to absolute zero. In this process, a group of atoms, typically bosons, occupies the lowest energy state available, leading to the formation of a unique coherent state. This state is characterized by a macroscopic occupation of the ground state, where many atoms behave like a single quantum entity rather than as individual particles.

In a Bose-Einstein condensate, these atoms lose their individual identities and exhibit properties such as superfluidity, allowing them to flow without viscosity. The phenomenon was first predicted by Satyendra Nath Bose and Albert Einstein in the early 20th century and was realized experimentally in 1995. The creation of a coherent state is significant in quantum mechanics as it demonstrates the wave-like behavior of particles on a macroscopic scale.

In contrast, other processes such as melting, forming a lattice structure, or dispersing into individual atoms do not occur during this particular transition and therefore do not characterize the nature of Bose-Einstein condensation.