Density-induced interchange of anisotropy axes at half-filled high Landau levels

The density-induced 90° rotations of the anisotropy axes in two dimensional electron gases (2DEG) at half-filled high Landau levels were studied. A tunable density heterostructure insulated gate field effect transistor (HIGFET) was used to calculate the transition density and observe hysteresis in the vicinity of the transition. A density-induced reorientation of the stripe state at v = 9/2 was observed. The low density orientation of the stripes was stabilized by an in-plane magnetic field applied along either anisotropy axis.