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Semiconductor billiards are often considered as ideal systems for studying dynamical chaos in the quantum mechanical limit. In the traditional picture, once the electron's mean free path, as determined by the mobility, becomes larger than the device, disorder is negligible and electron trajectories are shaped by specular reflection from the billiard walls alone. Experimental insight into the electron dynamics is normally obtained by magnetoconductance measurements. A number of recent experimental studies have shown these measurements to be largely independent of the billiard's exact shape, and highly dependent on sample-to-sample variations in disorder. In this paper, we discuss these more recent findings within the full historical context of work on semiconductor billiards, and offer strong evidence that small-angle scattering at the sub-100 nm length-scale dominates transport in these devices. This has important implications for the role these devices can play for experimental tests of ideas in quantum chaos. [ABSTRACT FROM AUTHOR]

Abstract: We demonstrate a novel heterostructure for inducing 2D hole systems in (311)A GaAs–AlGaAs heterostructures that offers advantages over previous methods including low turn on voltages, easier fabrication and good interface roughness. The heterostructure incorporates a metallic p+-GaAs cap layer as an in situ top gate that pins the Fermi energy close to the valence band and can then be used to induce the 2D hole system at the GaAs/AlGaAs interface. [Copyright &y& Elsevier]

We have developed and investigated a double-2DEG billiard to study the dependence of fractal conductance fluctuations on the soft-wall potential profile in semiconductor billiards. We use numerical modeling to establish how the profile differs between the billiards. We present preliminary results showing that the changes in profile modify the fractal dimension rather than suppress the fractal behavior, and that the fractal dimension depends inversely on the softness of the potential profile. [Copyright &y& Elsevier]

When semiconductor billiards are cooled to milli-Kelvin temperatures to preserve electron wave coherence, quantum interference effects generate reproducible fractal fluctuations in the billiard''s magneto-conductance. Here we show the fractal scaling properties to be remarkably robust to billiard shape. [Copyright &y& Elsevier]

Abstract: We compare directly the metallic behavior of high-quality, two-dimensional hole systems (2DHSs) in two GaAs device structures—one dominated by short-range disorder and the other by long-range disorder. We find that the type of disorder strongly affects the metallic behavior of the 2DHSs. In particular, we find that metallic behavior is enhanced in 2D systems with a high proportion of large-angle scattering events. [Copyright &y& Elsevier]