Condensed Matter and Statistical Physics Journal Club
|Date:||February 18, 2008|
|Title:||The ubiquitous wetting phase transition|
|Speaker:||Joseph Indekeu (Katholieke Universiteit Leuven, Belgium)|
|Abstract:||When we hear about wetting we spontaneously think of liquids spreading over surfaces or penetrating into absorbing materials. However, adsorption can take place in the context of any possible state of matter or combinations of such states. In this seminar, we will encounter various examples, sometimes of surprisingly different nature, which illustrate the adsorption of two coexisting phases at a third phase or "wall".
First, our attention will go to the wetting of oil (alkanes in particular) on water, relevant to oil recovery from porous rocks. A panoply of wetting phase transitions is possible in this system, and several have been observed experimentally.
Next, we will explore the arena of type-I superconductivity and examine how surface superconductivity can lead to wetting of the surface by the superconducting phase. Only very recently have systematic experiments provided strong evidence for a wetting phase transition in superconducting Sn.
Finally, the possibility of wetting phase transitions will be demonstrated in ultracold and extremely dilute gases, in a new state of matter corresponding to a mixture of Bose-Einstein condensates. The "wall" in this system is not a solid surface but an evanescent electromagnetic wave.