Landau theory magnetic field effects

The report of the Meissner effect stimulated the London brothers to develop the London equations, which explained this effect, and which also predicted how far a static external magnetic field can penetrate into a superconductor. The next theoretical advance came in 1950 with the theory of Ginzburg and Landau, which described superconductivity in terms of an order parameter and provided a derivation for the London equations. Both of these theories are macroscopic or phenomenological in nature. In the same year, 1950, the... 

Landau level A quantized energy level that occurs when an electrically charged particle is moving in an external magnetic field. The existence of such levels was predicted by Lev Landau in 1930. The concept of Landau levels is important in the theory of the quantum Hall effect. 

---