Sergey Kravchenko is professor of physics at Northeastern University, Boston, USA. He graduated from Moscow Institute of Physics and Technology, Russia, in 1982 and obtained his PhD from the Institute of Solid State Physics, Chernogolovka, Russia, in 1988. His research focuses on the low-temperature (millikelvin) properties of low-dimensional disordered systems by means of transport, capacitance, magnetization, and thermopower measurements. His primary interest is to understand the nature of the metallic state and the metal–insulator transition in strongly interacting 2D electron systems, discovered by him and his collaborators, and to determine its phase diagram. This discovery was listed among the 50 main discoveries in mesoscopic physics of the past century on the American Physical Society timeline in 1999 (“A Century of Mesoscopic Physics: 1899–1999”).