FRG: Coherence and Entanglement in Correlated Nanostructures

University Of Illinois At Urbana-Champaign, Urbana IL

Investigators

Abstract

****NON-TECHNICAL ABSTRACT**** The ability to control the flow of electrons through materials has been the key to technological progress in our society. Common electronic technology is based primarily on the ?classical? motion of electrons through metals or semiconductors. However, the next revolution in electronics will likely be based on the ?quantum mechanical? properties of electrons, such as their wave-like behavior and inherent ?spin?. These properties may form the basis of advanced cryptography and ultra-powerful ?quantum? computers. The goal of this research is to study and control such quantum electronics in nano-scale materials such as carbon nanotubes, superconducting wires, and magnetic wires. These materials are relevant because of their potential applications; they are also interesting because of the diverse phenomena stemming from their strongly interacting electrons. The research will target physics at the nano-scale, which is the next frontier for technology and where quantum properties are prevalent. A series of experiments supported by theories will work toward implementation of advanced quantum electronic devices and address fundamental, open questions regarding the behavior of electrons in nano-scale materials. The collaborative structure of the research will provide a rich environment for training undergraduates, graduate students, and postdoctoral researchers in a broad spectrum of nanotechnology and materials-related work. Educational aspects will be further integrated through the development of courses directly related to the proposed research and through research-related seminars and meetings that target high-school teachers, women, and underrepresented minorities. **** TECHNICAL ABSTRACT**** The goal of this project is to observe and characterize the properties of correlated electron pairs at nanoscale interfaces between superconductors and strongly-correlated materials. Coherent electron pairs emerging from superconducting sources will be studied in materials such as nanotubes, graphene, and ferromagnetic wires. In addition, methods for splitting injected Cooper pairs and then non-locally preserving quantum correlations will be developed, with the ultimate goal of realizing solid-state quantum entanglers. Experimental measurements of transport, phase coherence, and noise correlations will be supported by theoretical studies. The research will address major issues such as the influence of competing ordered states, the proximity effect at superconductor-correlated state interfaces, quantum phenomena in reduced dimensions, and optimal configurations for entanglement tests. This work will enable significant progress in our understanding of strongly-correlated nanoscale systems, and may form the basis of future solid-state quantum cryptography, teleportation, and quantum computation devices. The collaborative structure of the research will provide a rich environment for training undergraduates, graduate students, and postdoctoral researchers in a broad spectrum of nanotechnology-related work. Educational aspects will be further integrated through the development of courses directly related to the proposed research and through research-related seminars and meetings that target high-school teachers, women, and underrepresented minorities.