This is a condensed matter physics project in the area of two-dimensional electron systems (2DES), fabricated with delta-doped gallium arsenide/aluminum gallium arsenide multiple quantum wells. Such 2DES exhibit complex electrical transport behavior, such as the fractional quantum Hall effect (FQHE), when exposed to a magnetic field normal to the 2D planes. The 2DES will be investigated using a new technique called optically pumped nuclear magnetic resonance (OPNMR). The objective is to understand the nature of electron-electron interactions that are responsible for the FQHE. The OPNMR method is unique in providing specific information about the role of electron spin in the many-particle ground states, and elementary excitations, that give rise to the FQHE. This information can be related to novel geometrical magnetization distributions, called "skyrmions" that have been predicted in the 2DES and discovered via the OPNMR method. The project represents a frontier of condensed matter physics. The sophisticated materials required for the FQHE research are provided via a collaboration with Lucent Laboratories. The research provides an outstanding opportunity for graduate students to study fundamental physics and to learn cutting-edge experimental techniques that have applications in a wide area of semiconductor physics and the microelectronics industry. %%% This is a condensed matter physics project that deals with the electrical properties of electrons that are largely confined to move in a two-dimensional plane. These are two-dimensional electron systems (2DES). When a magnetic field is applied perpendicular to the plane of the electrons, and the electrical transport is measured, it is found that major changes occurs as a function of magnetic field. Some of this behavior is known as the fractional quantum Hall effect (FQHE). A full understanding of the FQHE is not available and the area represents a frontier of condensed matter physics. This project employs a unique nuclear magnetic resonance (NMR) method that senses the magnetic properties of the electrons that underlie the FQHE. The results are of fundamental interest and provide important tests of competing theories of the magnetism associated with the FQHE. The sophisticated materials required for the FQHE research are provided via a collaboration with Lucent Laboratories. The research provides an outstanding opportunity for graduate students to study fundamental physics and to learn cutting-edge experimental techniques that have applications in a wide area of semiconductor physics and the microelectronics industry.
