Electrodynamical properties of gapless edge excitations in the fractional quantum Hall states

Abstract

The electrodynamical properties of the edge excitations in the fractional quantum Hall (FQH) states are studied. We show how to experimentally measure the (optical) charges of the edge excitations. The interactions between the edge excitations are studied. We also discuss in detail the edge excitations of the \ensuremath{\nu}=1\ifmmode\pm\else\textpm\fi{}1/n FQH states. Measuring the dynamical properties of the edge excitations is a practical way to probe the topological orders in the FQH states.