LOCAL ELECTRON DENSITY PROFILE NEAR THE SAMPLE BOUNDARY INVESTIGATED BY MAGNETO-CAPACITANCE IN QUANTUM HALL REGIME

摘要

The spatial profiles of the electron density near the edge of narrow wires made from GaAs/AlGaAs heterostructure have been investigated using magneto-capacitance measurements in quantum Hall conditions. With decreasing the wire width below one micron, the profile of the electron density becomes steep and the electron density decreases due to the confinement potential at the boundaries of the wire. The extent of the depletion region and the local electron density near the wire edge is strongly influenced by the wire width, especially in sub-micron wires. The evaluation techniques of the local electron density profile near the edge are discussed in detail.