Non-Technical Abstract Low-dimensional systems, where particles are confined to one or two dimensions, is one of the major directions of modern condensed matter physics. These systems display many interesting behaviors, such as the quantum Hall effect, that do not occur in three dimensional materials. These unusual properties also make them of great interest for new devices and understanding these systems is also critical for progress in nanotechnology. Electrons on the surface of liquid helium was the first two-dimensional electron system discovered experimentally. It stands out as the most pristine two-dimensional system, as this system has no defects. Therefore studying it paves the way for understanding major physical phenomena in two dimensions without being hindered by imperfections. Because of the lack of disorder, the system is also of significant promise in terms of developing hardware for quantum information science. An important advantageous feature of the system is the possibility to control its parameters in a broad range, which enables characterizing various aspects of the system in a coherent fashion. As such, studying electrons on an helium surface provides a perfect ground for educating students interested in fundamental science and technology.
The proposed work is a joint experimental and theoretical effort with a dual aim. One goal is to understand the basic aspects of the electron dynamics that result from the strong electron correlations and the interaction with the quantum field of the vibrations of the helium surface. The other is the use of the system to study, in a well-controlled environment, the fundamental problems of condensed-matter physics that are hard to access in other systems because of defects. To this end, the proposed work will address the interplay of electron correlations and the coupling to a bosonic field in the response to resonant radiation; the change of the structure and the conductivity of the electron liquid and solid phases by spatially periodic electrostatic lattices; and the novel effects which emerge in a spatially periodic magnetic field and should provide an insight into new aspects of spin-orbit coupling in two-dimensional systems.
