3. Magnon Bose Einstein Condensation

 

In the first chapter we have seen what Bose-Einstein condensation is and how it is realized in atomic gases. In the second chapter I have introduced the concept of wave particle duality and quasi-particles. We have seen that elementary excitations in solid crystals can be treated like particles.

From these considerations it seems natural to apply the same statistical mechanics we already used for ordinary atoms to quasi-particles with the restriction that particle number is not conserved but variable due to the short lifetime and easy creation of them. This will lead to the conclusion that even in quasi-particle systems a phase transition like the Bose-Einstein condensation can occur.

This chapter starts with the question:

How can one achieve a Bose Einstein Condensation of Magnons?