Exotic Fractal Behavior
There are two important mechanisms that degrade conductivity of metals: disorder in the atomic array and mutual blocking of electrons. These mechanisms are known, respectively, as Anderson localization and the Mott metal-insulator transition. Phillip Anderson and Sir Neville Mott were awarded the Nobel Prize in Physics for their theories of these two mechanisms, yet unambiguous observations of these effects in real materials have remained elusive.
Using cold atoms in optical lattices, it is possible to introduce “controllable” disorder by superimposing quasi-periodic potentials and tuning the interactions by varying the lattice depth. Such systems are ideal laboratories for studying the interplay between interactions and disorder. We have studied the quantum coherence of strongly repulsive bosons, a. k. a. hard-core bosons, which are subject to quasi-periodic disorder. We have predicted the existence of phases with an exotic fractal nature in hard-core bosons.
PRA 73 063610(2006), New J. of Phys. 8, 155 (2006).
