Investigations of fundamental issues in strongly-correlated electron (SCE) systems form a major area of condensed matter research today. This program contains two main thrusts: (1) the observation and elucidation of new phenomena in SCE, and (2) the development of nanoscale devices using novel fabrication techniques both for the exploration of fundamental physics and for creating opportunities to capitalize on nano-physics to help meet the challenges of next-generation technological needs. The combination of fundamental research and the implementation of novel devices are designed to maximize the impact of this program, through scientific advances and the education/training of future researchers. Two genres of correlated systems--non-Fermi liquids in semiconductors, and metallic nanowires exhibiting correlated effects--will be studied. Non-Fermi liquid behavior constitutes a central theme of SCR systems. Unusual metallic behaviors observed in the normal state of high-Tc superconductors and in one-dimensional conductors are pushing beyond the standard Fermi liquid picture for conventional metals, toward a possible new paradigm of non-Fermi liquids in low-dimensional correlated systems. Two such systems are studied by transport measurements, the chiral Luttinger liquid at the 1-dimensional edge of the fractional quantum Hall fluid, and the two impurity Kondo system in double-quantum-dots. The edge of the fractional quantum Hall fluid supports exotic fractionally-charged quasi-particles obeying fractional statistics which will be investigated. Work in double-quantum-dots serves a dual purpose. In addition to exploring non-Fermi liquid behavior, the implementation of this system as a prototypical 2-qubit system will be pursued to create a building block of a semiconductor-based quantum computer. From a long term perspective, this may have a profound impact on bringing the challenging task of implementing quantum computation closer to reality. In metallic wires, investigation will concentrate on the phenomena of superconductivity, magnetism, etc., in nanowires fabricated by a novel cleaved-edge technique, as well as interaction between adjacent wires running parallel to each other. Understanding the properties of nanowires in proximity may impact next generation interconnects as device density in ULSI increases further. This program will train students in nanoscience and technology with an emphasis in nano-fabrication techniques and ultra low-noise electrical measurements. Such skills are particularly valuable for preparing the students to help drive forward the all important nano-science technology revolution which forms the basis of the technology and economic engine of the 21st century. %%% Investigations of strongly-correlated electron (SCE) systems form a major area of condensed matter research today. This program contains two main thrusts: (1) the observation and elucidation of new phenomena in strongly- correlated systems, and (2) the development of nanoscale devices using novel fabrication techniques both for the exploration of fundamental physics and for creating opportunities to capitalize on nano-physics to help meet the challenges of next-generation technological needs. The combination of fundamental research and the implementation of novel devices is designed to maximize the impact of this program, through scientific advances and the education/training of future researchers. Strong correlations between electrons lead to unusual and novel metallic behaviors. Examples include high temperature superconductors and other low-dimensional conductors such as 0- and 1-dimensional conductors. Non-Fermi liquid behavior constitutes a central theme of SCE systems. For these systems, a new paradigm beyond the standard picture for conventional metals may become necessary. Two such systems will be studied by electrical measurements, the chiral Luttinger liquid at the 1-dimensional edge of the fractional quantum Hall fluid, and the two impurity Kondo system in double-quantum-dots. The edge of the fractional quantum Hall fluid supports exotic particles which carry charges in fractional units of the fundamental electron charge. Work in double-quantum-dots serves a dual purpose. In addition to exploring non-Fermi liquid behavior, the implementation of this system as a 2-quantum qubit system will be pursued to create a building block of a semiconductor- based quantum computer. If successful this may have a profound impact in the long term on bringing quantum computation to reality. In metallic wires, investigation will concentrate on the phenomena of superconductivity, magnetism, etc., in nanowires as well as interaction between wires in close proximity. Understanding the properties of nanowires in proximity may impact next generation interconnects as device density in ULSI increases further. This program will train students in nanoscience and technology with an emphasis in nano-fabrication techniques and ultra low-noise electrical measurements. Such skills are particularly valuable for preparing the students to help drive forward the all important nano-science technology revolution which forms the basis of the technology and economic engine of the 21st century.
