Extended group picture, 56.8 Million Celebration dinner in Element, June 24, 2021

Group picture, Sourland Mountain Preserve, Oct 11, 2022

Mansour Shayegan

Our research group focuses primarily on the physics of semiconductors, with an emphasis on their electronic properties. Our work involves the growth of Gallium Arsenide/Aluminum Gallium Arsenide (GaAs/AlGaAs) heterostructures by molecular beam epitaxy, and studies of ballistic and quantum transport in these structures. Of particular interest are the many-body phenomena observed in these low-dimensional structures at low temperatures and high magnetic fields. Our research includes the fabrication, via molecular-beam epitaxy followed by various lithography techniques, of very clean (low-disorder) quantum-confined carrier systems, as well as 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, allowing us to study ballistic and phase-coherent transport. 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 superlattices, density-modulated systems, wide parabolic quantum wells, quantum wires and dots, and single- and multilayer electron and hole systems.