University of Chicago

Title: Tunneling between Two Laterally Coupled Quantum Hall Systems

Abstract: Over 20 years has passed since the discoveries of the integer and fractional quantum Hall effects. Recently it has become possible to realize high quality tunnel junctions between two quantum Hall systems, potentially leading to development of quantum Hall effect based devices. In this talk, study of tunneling between two laterally separated quantum Hall systems will be presented. Using cleaved edge overgrowth, a co-planar tunnel barrier is inserted between two quantum Hall droplets, and the resultant tunnel junctions juxtaposes two counterpropagating edge states of the quantum Hall droplets against the barrier. Due to the quality of the tunnel barrier and the ballistic property of the quantum Hall edge states, interaction effects become predominant and disorder plays a negligible role to the leading order. Tunneling strongly mix the single particle states of the edge states, and the inter-edge correlation transforms the two counterpropagating edge states into a system of highly correlated coupled one-dimensional system. Prospect for realization of coherent tunneling between two lateral quantum Hall systems will be discussed.