Transport in ferromagnet/semiconductor 2DEG hybrid network structure

We have investigated transport in a network of narrow two-dimensional electron gas (2DEG) channel under a gradient magnetic field which is generated by a network of cobalt film deposited on the surface. Resistance of the 2DEG network changed with the magnetization of the cobalt network. The gradient magnetic field breaks the symmetry of the system with respect to the direction along the channel. We have found that the differential resistance under a finite DC bias current depends on the current direction. Magnetoresistance as a function of uniform perpendicular magnetic field while keeping the gradient field constant exhibits an overall shift and modulation of Shubnikov de-Haas oscillations.