Super-fluid 4He - (two domains)

[ibysaiyan]

Hi PF ,

I am making a review article which is mainly based on low temperature physics , upon going through my search I have stumbled across the famous " Lambda transition" of super liquid helium. Paraphrasing what some of the books said : " In the He II domain a percentage of atoms in same quantum state act as a single entity , while the rest of the percentage is made up of atoms which have different quantum states ( another book says normal , what do they mean by normal ? vector [position ?] , the overall density stays constant " .

I need bit of a clarification on the bold bit , also it's said that as the temperature is dropped to absolute zero , the number of atoms ( normal) decreases.

I know that in Q.M particles are said to obey einstein-bose statistics if they have an integer spin of zero , so in what way is He II similar to Bose- Einstein condensate.

I appreciate your help.

-ibysaiyan

 

[Wolfgang2b]

You need to check the two fluid model for superfluids. Here is one link I got from Google

http://www.yutopian.com/Yuan/TFM.html

Normal fluid represents the non-superfluid part. Nothing to do with vectors.

He-II is a BEC because all of the He atom are in the ground state and can be described by a single wave function.