INDUCTIVE PROBING OF THE INTEGER QUANTUM HALL-EFFECT

We investigated the integer quantum Hall effect (IQHE) using an induct ive method. The following conclusions can be derived from our study: ( i) When the Fermi energy is located between Landau levels the only ext ended states at the Fermi energy are located at the physical edges of the sample. (ii) The extended states located at the bulk of the sample below the Fermi energy are capable of carrying a substantial amount o f Hall current, but cannot screen an external electrostatic potential.