# Why superconductor have vortex

Sorry guys I really don't understand the idea of vortex in superconductor, why superconductors type II have vortices ?

• Do you mean an Abrikosov vortex? Have you tried Googling them? Can you be more specific about what you don't understand? – John Rennie Nov 25 '15 at 16:24
• @petersmith Type II superconductor have 3 types of vortices, as far as i understand it, vortices are structural defects, but how this defects so special in superconductor? – Raldenors Nov 26 '15 at 2:45
• They are special because they are defect of the order parameter. They retain quantised flux inside the superconductor. I've never heard about three different kind of vertex. This question deserve details to be answered. Please first read -- at least -- wikipedia and references therein and then come back with a precise question that we might hope to answer. At the moment, it seems that you're asking "why type-I superconductors don't have vortices ?" – FraSchelle Nov 26 '15 at 16:30

• Coherence length $\xi$
• Penetration depth $\lambda$
Depending on the ratio between this two lengths ($\kappa = \lambda/\xi$) it will be energetically favourable or not to create superconductor-normal conductor interfaces when increasing the applied magnetic field. Therefore we have two types of superconductors:
• Type I: $\kappa \in (0,1\sqrt{2})$. Does not create superconductor-normal conductor interfaces.
• Type II: $\kappa > 1\sqrt{2}$. Creates superconductor-normal conductor interfaces (vortices)