Superconductors and quasiparticles

[Niles]

Hi

I read on Wikipedia that a broken Cooper pair is called a Bogoliubov quasiparticle (source: http://en.wikipedia.org/wiki/Quasiparticle). Is that really true (if yes, then is there a difference between QPs in a metal and a superconductor)?

 

[ZapperZ]

A "quasiparticle" is a concept out of Landau's Fermi Liquid Theory. It is the result of the "renomalization" of the many-body interaction in the weak-coupling limit. It applies to most metails. And since conventional superconductors are predominantly these "standard" metals, the quasiparticles are the same because these are renormalized electrons.

In cuprate superconductors, that's a different story. Because of strong coupling, these quasiparticles many not be the same ones you get in metals. In fact, that's why the normal state of these material are often called "bad metals", because the behavior of these quasiparticles are not what one would expect out of the Fermi Liquid theory.

Zz.

 

[genneth]

Pedantic point: the Bogoliubov particles in SC are not quite electrons, but a mixture of electron and hole excitations. Sort of. At the end of the day, it doesn't make immediate sense to talk about excitations of a different ground state and assume that they behave anything like each other.