Type-1.5 superconductivity

Superconductivity is a state where electric charge flows without resistance. In Type-I and Type-II superconductors the charge flow patterns are dramatically different. Type I was discovered a century ago. In response to a weak magnetic field it creates a supercurrent near its surface and expels the applied magnetic field from its interior. Type II superconductivity was experimentally discovered by Shubnikov in 1937. Applied magnetic field can gradually penetrate this type of superconductors. In mid-1950, A.A.Abrikosov explained type-II behavior as a formation of an exotic and counter-intuitive state of a regular lattice of quantum vortices. In this talk, after an overview of 100 years of progress in understanding of superconductivity and quantum fluids in general, I will argue that some of newly discovered materials can have a new kind of superconductivity which breaks the type-I/type-II dichotomy and can form novel phases in applied magnetic field.