LOCAL CURRENT DISTRIBUTION IN THE PRESENCE OF NONEQUILIBRIUM DISTRIBUTION OF EDGE STATES

Local current distribution in the presence of nonequilibrium distribution between different edge states in a quantum Hall effect regime is theoretically studied by explicitly taking into account extra charge added into edge states. The extra charges produce a Hall electric field that induces Hall current I-H. Total current is the sum of I-H and the chemical-potential edge current I-CE carried by the extra charges themselves. The calculation shows that I-CE much less than I-H When the local current distribution is represented by a ''response current density j(R),'' it generally spreads out into the interior region of a conductor, while its amplitude increases as the sample boundaries are approached. When the local current distribution is represented by a ''Fermi-surface current density j(F),'' it is strictly localized at the edge states.