Abstrakt: |
In 1980, an altogether unexpected discovery was made by Klaus von Klitzing and coworkers [1] when carrying out Hall measurements on a metal-oxide-semiconductor field-effect transistor (MOSFET) . They discovered that for a system of electrons confined to two dimensions and subject to a strong, perpendicular magnetic field, B, the resistivity tensor, ρ, and the conductivity tensor, σ, can freeze to the form with j being an integer3. Astonishingly, it turned out that this quantisation holds over a wide range of B or the applied voltage, forming quantised plateaus, and is independent of the sample geometry and choice of material. [ABSTRACT FROM AUTHOR] |