Metal-insulator transition in two dimensions
Mardi 09/05/2006, 11:00
SPEC Salle Itzykson, Bât.774, Orme des Merisiers
(Séminaire général commun SPhT-SPEC)
The observation of a 2D metal-insulator transition was first reported by S. V. Kravchenko, G. V. Kravchenko, J. E. Furneaux, V. M. Pudalov (Phys. Rev. B 50, 8038 (1994)). A recent theory of this transition (Punnoose and Finkelstein, Science 310, 289 (2005)) explains all the most striking features of this phenomenon, including the temperature-independent separatrix between metallic and insulating phases, quenching of the metallic state by a magnetic field, critical behavior of the spin susceptibility and dramatic enhancement of the effective mass in the vicinity of the transition. I will review the key experimental facts and make a detailed comparison between experiments and the theory.