Exact definitions of BEC for real gases-liquids?

In summary: However, there is still debate and ongoing research in the physics community about the exact definition and properties of BEC for real gases, especially those with hard core potentials or strong interactions. Despite this, it is generally accepted that BEC is a phenomenon that occurs when a large number of particles in a system behave as a single entity, exhibiting wave-like properties.
  • #1
Minich
87
1
While reading papers on various topics in physics i have become very embarrassed with the meaning of such a word as BEC.
Even in peer-reviewed papers i can't find any attempt to give exact definition of BEC for real gases.
For such topics as:
Electron (pair-ed, superfluid) gas, 2D (! do you know about 2D BEC?) (superconducting "pair-ed") electron gas, atomic nucleus, pion condensation, real 4He...

As everybody knows BEC is the effect of ideal bose gas, and i guess BEC must be clarified when this term is applied to real gases (liquids!).
What will happen with BEC if we consider (only!) the mass of container with ideal bose gas and give the container freedom to rotate and move? Or vibrate...

What will be with this container (for example cube container), if we take Andronikashvili-like experiment with "BEC" inside it?

My question is:
How many "exact" definitions of BEC for real gases do exist?
Especially for gases with hard core potentials or strong interacting gases.

Let us collect such definitions here and discuss them.
 
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  • #2
BEC is generally defined as a state of matter where a large number of particles occupy the lowest energy state. In the case of a real gas, this means that all particles in the system must be in the same quantum state and have the same momentum. This is typically referred to as a condensate. The BEC can also be achieved through cooling a gas to very low temperatures, during which a large portion of the particles in the gas will become indistinguishable and form a coherent state. This process is known as Bose-Einstein condensation.
 
  • #3


it is important to note that the concept of Bose-Einstein condensation (BEC) was originally developed for ideal gases, where the particles do not interact with each other. However, as research has progressed and more complex systems have been studied, the definition of BEC has evolved to include real gases and liquids.

One possible definition of BEC for real gases could be that it is a phenomenon where a large number of particles in a gas or liquid occupy the same quantum state, leading to macroscopic quantum effects. This definition takes into account the fact that in real gases, particles do interact with each other and therefore the concept of a single quantum state may not be applicable. Instead, a range of states may be involved in the BEC phenomenon.

Another definition could be that BEC is the point at which a gas or liquid undergoes a phase transition and becomes a coherent state, with all particles occupying the same energy level. This definition is based on the idea that BEC is a macroscopic quantum effect that occurs at low temperatures and high densities, where the particles are more likely to interact and condense into a single state.

For gases with hard core potentials or strong interactions, the definition of BEC may need to be modified to account for these additional factors. For example, in the case of a gas with a hard core potential, the particles may not be able to occupy the same space, leading to a different type of condensation than in an ideal gas.

In terms of the Andronikashvili-like experiment mentioned in the content, it is important to consider the specific conditions and parameters of the experiment in order to determine if it can be classified as a BEC. The concept of BEC is a complex and evolving one, and it is important to carefully define and understand it in the context of different systems and experiments.

In conclusion, there is no one "exact" definition of BEC for real gases and liquids, as it is a complex phenomenon that can manifest in different ways depending on the system being studied. It is important for scientists to carefully define and understand the concept of BEC in order to accurately apply it to their research and experiments.
 

1. What is BEC for real gases and liquids?

BEC stands for Bose-Einstein condensation, which is a phenomenon that occurs when a large number of bosons (particles with integer spin) occupy the same quantum state at low temperatures. In real gases and liquids, BEC refers to the transition of a gas or liquid from the normal state to a state of matter where the particles behave as if they are all in the same quantum state.

2. How is BEC defined for real gases and liquids?

The exact definition of BEC for real gases and liquids is based on the condensate fraction, which is the ratio of the number of particles in the condensed state to the total number of particles. In order for BEC to occur, the condensate fraction must be greater than zero at low temperatures.

3. What is the critical temperature for BEC in real gases and liquids?

The critical temperature for BEC in real gases and liquids is the temperature at which the condensate fraction becomes non-zero. This temperature varies depending on the properties of the gas or liquid, but it is typically extremely low, in the range of nanokelvins to microkelvins.

4. Can BEC occur in all real gases and liquids?

No, BEC can only occur in gases and liquids composed of bosonic particles. This includes some atoms, such as helium-4, and certain molecules, but excludes most common gases like oxygen and nitrogen which are composed of fermionic particles.

5. What are the applications of BEC in real gases and liquids?

BEC has many potential applications, including in quantum computing, precision measurements, and creating new states of matter for studying fundamental physics. It is also being studied for potential applications in superfluids and superconductors, which could have practical uses in technology and energy production.

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