Quantum transport in lattices of coupled electronic billiards

A new system with dynamic chaos — 2D lattice of single Sinai billiards coupled through quantum dots — is studied experimentally. Localization in such a system was found to be substantially suppressed, because the characteristic size of the billiard for $g\leq1$ ($g$ is conductance measured in $e^2/h$ units) is the localization length rather than the de Broglie wavelength of an electron, as in the usual 2D electron system. Lattice ballistic effects (commensurate peaks in the magnetoresistance) for $g\ll1 $, as well as extremely large magnetoresistance caused by the interference in chaotic electron trajectories, were found. Thus, this system is shown to be characterized by simultaneous existence of effects that are inherent in order (commensurate peaks of magnetoresistance), disorder (percolation charge transport), and chaos (weak localization in chaotic electron trajectories).