Theory of 2D metal-insulator transition I: Zero Magnetic field
  We propose a scaling theory of 2D metal insulator transition discovered by Kravchenko and coworkers. In this theory conductance/resistance duality is an exact relation. The exponent of the stretched exponential in $\sigma(T)$ is determined by the temperature dependence of the coherence length. The quantum-chaotic nature of the transition is manifested in the square form of the phenomenological scaling function. 
Konstantin Kladko