Magnetoresistance oscillations in a modulated 2DEG periodic in the ratio h/e to flux per unit cell

Transport properties of the 2DEG are studied in the presence of a normal magnetic field B and of a weak, two-dimensional periodic potential modulation. A tight-binding treatment has shown that each Landau level splits into several subbands with exponentially small gaps between them. Assuming the latter are closed due to disorder gives analytical wave functions and simplifies the evaluation of the magnetoresistance tensor ρμν. The relative phase of the oscillations in ρxx and ρyy depends on the modulation strengths and periods. For short periods View the MathML source, in addition to the Weiss oscillations, the collisional contribution to the conductivity and the corresponding resistivity contribution show prominent peaks when one flux quantumh/epasses through an integral number of unit cells in good agreement with experiments. For periods View the MathML source long used in early experiments, these peaks occur at fields 10–25 times smaller than those of the Weiss oscillations and are not resolved.