Edge reconstructions in fractional quantum Hall systems

Two-dimensional electron systems exhibiting the fractional quantum Hall effects are characterized by a quantized Hall conductance and a dissipationless bulk. The transport in these systems occurs only at the edges of the incompressible quantum Hall regions, where gapless excitations are present. We present a microscopic calculation of the edge states in the fractional quantum Hall systems at various filling factors using the extended Hamiltonian theory of the fractional quantum Hall effect. We find that at $\ensuremath{\nu}=1/3,$ the quantum Hall edge undergoes a reconstruction as the background potential softens, whereas the quantum Hall edges at higher filling factors, such as $\ensuremath{\nu}=2/5,3/7,$ are robust against reconstruction. We present the results for the dependence of the edge states on various system parameters such as temperature, functional form and range of electron-electron interactions, and the confining potential. Our results have implications for the tunneling experiments into the edge of a fractional quantum Hall system.