Transport properties of two-dimensional electrons in periodically modulated magnetic fields

We study both classical and quantum transports in two-dimensional electron gas (2DEG) numerically, where magnetic fields are applied perpendicular to the plane of 2DEG and are periodically modulated. Due to the non-homogeneous magnetic fields, the system becomes chaotic. In the classical model, we show the commensurability oscillation of magnetoresistance in periodic magnetic fields. The negative magnetoresistance is observed when the conductivity σxx is small. The quantum transport is also investigated, and the universal conductance fluctuations as well as the fractal behavior of the magnetoconductance are observed.