High-Sensitivity Measurements of Interacting Disordered Quantum Hall Systems

University Of California-Los Angeles, Los Angeles CA

Investigators

Abstract

Technical This individual investigator award supports a project to investigate interacting disordered electrons in semiconductor heterostructures. High-frequency measurements in radio and microwave frequency ranges will be developed to address a set of questions that cannot directly be answered by more standard transport techniques. An emphasis of the investigations will be on how spin/charge interactions can influence the ground state properties of electrons when two sets of Landau levels are brought into degeneracy. The study will be facilitated by using resistively detected nuclear magnetic resonance and microwave absorption spectroscopy techniques in a GaAs/AlGaAs quantum well with two occupied subbands. Another focus of the research will be on the search for broken-symmetry magnetic and spin-paring states of highly correlated electrons. High-frequency spectroscopy studies will be done in strained Si/SiGe heterostructures. The results anticipated from these experiments may have applications in high-frequency electronics. The hands-on research, which will include microwave engineering and characterizations, will give graduate and undergraduate students excellent training in the important technical area of microwave electronics. Nontechnical: This individual investigator award supports an experimental research project involving high-frequency studies of advanced semiconductor devices. These electronic devices are very similar to those widely used in high-speed electronics and in information processing. The main objective of the project is to understand a set of newly-discovered electronic properties stemming from the intricate interactions between two electrons due to a property of electrons called electron spin. The ability to gain such understanding will be made possible by using an array of unconventional high-frequency techniques. The results anticipated from these experiments may have broader impacts on the development of the next generation of semiconductor devices. For example, devices using electron spins to perform information processing via memory and logic functionality are gradually emerging. The capability to measure and manipulate electron spins at high frequencies may become an important part of the development of these new devices. The heavy hands-on research, which will include microwave engineering and characterizations, will give graduate and undergraduate students excellent training for microwave electronics, a technological area that is of great economic importance to our society.