CAREER: Strongly Correlated Quantum Phenomena in Low-Dimensional Systems

University Of Illinois At Urbana-Champaign, Urbana IL

Investigators

Abstract

TECHNICAL SUMMARY: This CAREER award supports theoretical research and education on strongly correlated quantum phenomena in low-dimensional systems. The research plan employs a common set of theoretical techniques to explore strongly correlated physics in three such systems which have drawn the attention of the scientific community and have been the focus of cutting-edge experimental investigations: 1) carbon nanotubes, 2) trapped atomic systems and 3) fractional quantum Hall systems. These systems address complementary aspects of low-dimensional systems and have both fundamental and technological value. The major focus of this research program will in three specific arenas: i) Luttinger-liquid physics and spin-charge separation: Probes and characteristic signatures of the Luttinger-liquid physics, which is characteristic of one dimension, will be explored in nanotubes and trapped atomic systems with emphasis on spin-charge (density) separation. Novel physics, only recently observed in solid state systems, will be explored in the trapped atomic clusters by exploiting the unprecedented level of tuning capability that is possible. ii) Quantum dot physics in nanotubes: Short nanotubes placed between tunnel contacts have displayed quantum dot behavior, which could be exploited for quantum-device applications. The quantum states of such nanotubes will be characterized, and schemes will be proposed for realizing quantum entanglement in coupled tubes. iii) Measurement of fractional statistics: The prospect of detecting fractional statistics in quantum Hall systems will be investigated. The intent is to identify experimental consequences that may be described for measurements and analyses which will permit identification of clear-cut signatures of fractional quantum numbers. The education component consists of interconnected plans for education and outreach that span high school to graduate level education, seek to enhance participation of underrepresented groups, and include an international dimension. Included in this activity are workshops for women faculty, researchers, and students; interaction with Wellesley to share and develop educational resources for undergraduates; outreach to local high schools that is stimulated by the PI's collaboration on outreach activities with the Bangalore Association for Scientific Education in India; and specific contributions to "discovery-style" experimental units in a sweeping revitalization of laboratory courses. NON-TECHNICAL SUMMARY: This CAREER award supports theoretical research and education into the unusual physics that underlies the complex behaviors of very small electronic systems and electrons that are confined to planes or lines. The award also supports education, particularly as it relates to the new area of nanotechnology, through the involvement of students in the research and a range of outreach efforts at both the local and international level. The research effort investigates electronic structure of small assemblies of atoms, including carbon nanotubes which have a rapidly growing role in nanotechnology. Theoretical techniques will be developed and used to describe the incompletely-understood electronic properties of materials when employed in extremely miniaturized devices. These will necessarily employ quantum theory governing the dynamics of such small systems and build on and extend the recent advances in applying the theoretical techniques to small nanoscale structures. The research has both theoretical and technological value. It is designed to engage directly issues encountered in ultra-small experimental systems that are now receiving intense scrutiny by researchers in experimental physics and technology-focused investigations. From the technological perspective, these studies of quantum physics in small confined materials will be supportive of work towards building nanoscale devices and realizing future technological advances put forth by the newly emerging field of quantum information science.