BOSE-EINSTEIN CONDENSATE: PROPERTIES AND APPLICATIONS - PHYSICAL - 2025

The Bose-Einstein condensate is a state of matter that occurs in certain particles at temperatures near absolute zero. For a long time it was thought that the only three possible states of aggregation of matter were solid, liquid, and gas.

Then the fourth state was discovered: that of plasma; and the Bose-Einstein condensate is considered the fifth state. The characteristic property is that the particles in the condensate behave as a large quantum system rather than as they usually do (as a set of individual quantum systems or as a grouping of atoms).

In other words, it can be said that the entire set of atoms that make up the Bose-Einstein condensate behaves as if it were a single atom.

Origin

Like many of the more recent scientific discoveries, the existence of the condensate was theoretically deduced before there was empirical evidence of its existence.

Thus, it was Albert Einstein and Satyendra Nath Bose who theoretically predicted this phenomenon in a joint publication in the 1920s. They did so first for the case of photons and then for the case of hypothetical gaseous atoms.

The demonstration of their real existence had not been possible until a few decades ago, when a sample was cooled to temperatures low enough to verify that what the equations anticipated was true.

Satyendra Nath Bose

Obtaining

The Bose-Einstein condensate was obtained in 1995 by Eric Cornell, Carlo Wieman and Wolfgang Ketterle who, thanks to it, would end up sharing the 2001 Nobel Prize in Physics.

To achieve the Bose-Einstein condensate they resorted to a series of atomic physics experimental techniques, with which they managed to reach a temperature of 0.00000002 degrees Kelvin above absolute zero (a temperature much lower than the lowest temperature observed in outer space)..

Eric Cornell and Carlo Weiman used these techniques on a dilute gas made up of rubidium atoms; for his part, Wolfgang Ketterle applied them shortly afterwards on sodium atoms.

Bosons

The name boson is used in honor of the Indian-born physicist Satyendra Nath Bose. Two basic types of elementary particles are considered in particle physics: bosons and ferminions.

What determines whether a particle is a boson or a fermion is whether its spin is integer or half integer. Ultimately, bosons are the particles in charge of transmitting the forces of interaction between fermions.

Only bosonic particles can have this state of Bose-Einstein condensate: if the particles that are cooled are fermions, what is achieved is called a Fermi liquid.

This is so because bosons, unlike fermions, do not have to meet the Pauli exclusion principle, which states that two identical particles cannot be in the same quantum state at the same time.

All atoms are the same atom

In a Bose-Einstein condensate all the atoms are absolutely the same. In this way, most of the atoms in the condensate are at the same quantum level, descending to the lowest possible energy level.

By sharing this same quantum state and all having the same (minimum) energy, the atoms are indistinguishable and behave as a single “super atom”.

Properties

The fact that all atoms have identical properties supposes a series of certain theoretical properties: the atoms occupy the same volume, scatter light of the same color and a homogeneous medium is constituted, among other characteristics.

These properties are similar to those of the ideal laser, which emits a coherent light (spatially and temporally), uniform, monochromatic, in which all the waves and photons are absolutely the same and move in the same direction, ideally not dissipate.

Applications

The possibilities offered by this new state of matter are many, some truly amazing. Among the current or in development, the most interesting applications of Bose-Einstein condensates are the following:

- Its use together with atom lasers to create high precision nano-structures.

- Detection of the intensity of the gravitational field.

- Manufacture more precise and stable atomic clocks than those that currently exist.

- Small-scale simulations for the study of certain cosmological phenomena.

- Applications of superfluidity and superconductivity.

- Applications derived from the phenomenon known as slow light or slow light; for example, in teleportation or in the promising field of quantum computing.

- Deepening of the knowledge of quantum mechanics, carrying out more complex and non-linear experiments, as well as the verification of certain recently formulated theories. Condensates offer the possibility of recreating phenomena that occur light years away in laboratories.

As can be seen, Bose-Einstein condensates can be used not only to develop new techniques, but also to refine some techniques that already exist.

Not in vain do they offer great precision and reliability, which is possible due to their phase coherence in the atomic field, which facilitates great control of time and distances.

Therefore, Bose-Einstein condensates could be as revolutionary as the laser itself was once, since they have many properties in common. However, the big problem for this to happen lies in the temperature at which these condensates are produced.

Thus, the difficulty lies both in how complicated it is to obtain them and in their costly maintenance. For all these reasons, at present most efforts are mainly focused on its application to basic research.

Bose-Einstein condensates and quantum physics

The demonstration of the existence of Bose-Einstein condensates has offered an important new tool for studying new physical phenomena in very diverse areas.

There is no doubt that its coherence at the macroscopic level facilitates both the study and the understanding and the demonstration of the laws of quantum physics.

However, the fact that temperatures close to absolute zero are necessary to achieve this state of matter is a serious drawback to get more out of its incredible properties.

References

1. Bose – Einstein condensate (nd). On Wikipedia. Retrieved on April 6, 2018, from es.wikipedia.org.
2. Bose – Einstein condense. (nd) In Wikipedia. Retrieved on April 6, 2018, from en.wikipedia.org.
3. Eric Cornell and Carl Wieman (1998). Bose-Einstein Condensates, "Research and Science."
4. A. Cornell & CE Wieman (1998). "The Bose – Einstein condensate". Scientific American.
5. Boson (nd). On Wikipedia. Retrieved on April 6, 2018, from es.wikipedia.org.
6. Boson (nd). On Wikipedia. Retrieved on April 6, 2018, from en.wikipedia.org.