The research in my group is primarily on the physics of semiconductors, with an emphasis on their electronic properties. Our work involves the growth of GaAs/AlGaAs heterostructures by molecular beam epitaxy, and studies of ballistic and quantum transport in them. Of particular interest are the many-body phenomena observed in these low-dimensional structures at low temperatures and high magnetic fields.
Our research includes both the fabrication, via molecular beam epitaxy followed by various lithography techniques, of very clean (low-disorder) quantum-confined carrier systems, and measurements of their electronic transport properties. The systems we are studying, namely, novel, high-quality quasi-two-dimensional electron and hole systems in selectively doped GaAs/AlGaAs heterojunction structures, are among the cleanest carrier systems available. In these structures, the mobile carriers are spatially separated from the dopant (impurity) atoms to minimize scattering. As a result, the mean-free-path of carriers at low temperatures reaches several microns, so that ballistic and phase-coherent transport can be studied. Such structures also provide a crucial and important test bed for new many-body physics, since the dominant interaction at low temperatures is the repulsion between the electrons themselves.
In our work we study ballistic and phase-coherent transport, as well as many-body phenomena, in a variety of structures such as single- and multilayer electron and hole systems, wide parabolic quantum wells, superlattices, density-modulated systems, and quantum wires and dots.