SERIES OF MAGNETORESISTANCE OSCILLATIONS OF A 2-DIMENSIONAL ELECTRON-GAS IN A STRONG PERIODIC MAGNETIC MODULATION

A nonperturbative technique is used to calculate the magnetoresistance of two-dimensional electron gases (2DEG) subjected to a spatially per iodic magnetic field B-1 with period a in addition to a uniform magnet ic field B-0 in the same direction. For small amplitude modulation, ma gnetoresistance exhibits oscillations similar to the Weiss oscillation s observed in 2DEG under spatially periodic electric field and uniform magnetic field. In general, the oscillation is characterized by two r atios: beta = 2 pi l/a and gamma = B-1/B-0, at low magnetic modulation s, with l being the magnetic length corresponding to B-0. Quenching of Weiss oscillations first appears as gamma increases for fixed B-0, an d a series of oscillations then appears in our nonperturbative calcula tion for larger gamma. The temperature dependence of these oscillation s shows that the basic mechanism of the production of these oscillatio ns is similar to the Weiss oscillations.