Anderson Transition.

Quantum mechanics lies at the heart of modern technology. Semiconductors which are fundamental objects in every electronic device depend on quantum mechanical behaviour of electrons and their interaction with lattice structure. One of the interesting phenomena called Anderson transition was reported by Anderson when he found that electrons which should exist as spatially extended states in perfect crystals, eventually localize as the amount of disorder in the crystal increases. Experimentally, however, it has proven very difficult to create the right conditions to observe the transition. Now Julien Chabé and colleagues at the Université des Sciences et Technologies de Lille and the Université Pierre et Marie Curie in Paris have demonstrated an equivalent of the Anderson transition for electrons by trapping cold atoms in a periodic, optical potential. Their experiment, reported in Phys. Rev. Lett. 101, 255702 (2008) – (Published December 15, 2008) overcomes previous difficulties associated with observing the transition in cold atom gasses and also holds the promise of extending the study of the Anderson transition to higher dimensions