Temperature Dependence of Electron Channelling via Magnetic Edge States

We report on the temperature dependence of the magnetoresistance in a twodimensional electron gas subjected to an abrupt magnetic field gradient. The gradient leads to the formation of snake states and cycloid states that drift perpendicular to it. By studying changes in the magnetoresistance in the temperature range 1-40K we show significantly different behaviour for these two types of magnetic orbit. Snake states have a robust temperature dependence because of their vanishingly small period whereas cycloid states have a similar period to closed cyclotron orbits. This interpretation is supported by a drift diffusion model comparing the elastic scattering time to the period of both orbits. The Shubnikov-de Haas oscillations are also studied and exhibit a decline over the same temperature range as the cycloid states whilst the snake states remain largely unaffected.