We have extended earlier measurements of the magnetoresistance in a periodically modulated two-dimensional electron gas to high magnetic fields, where the cyclotron radius, r(c), is much smaller than the period, a, of modulation. A giant nonoscillatory magnetoresistance was found to arise beyond the range of low-field (Weiss) oscillations periodic in 1/B. Its value in a magnetic field of a few tesla may exceed the zero-field resistance value, rho-0, by 1 to 2 orders of magnitude. This result is in agreement with the semiclassical theory by Beenakker, if a modulation of the electron mobility is taken into account.
|Journal||Physical Review B|
|Publication status||Published - 1992|