Magnetically induced Bragg scattering of electrons in quantum-dot crystals

We demonstrate a novel manifestation of dynamic Bragg reflection in artificial quantum-dot crystals that is driven by the application of a magnetic field. This backscattering is coherently cascaded as the number of dots in the structure is increased, causing a superlinear damping of the electron wave function and the appearance of a series of gaps in the miniband spectrum. The evolution of the dynamic miniband structure as the magnetic field is varied gives rise to behavior analogous to a metal-insulator transition, which is manifest as a dramatic resonance in the magneto-resistance of the structures.