Temperature Dependence of Electron Channelling viaMagnetic Edge States

摘要

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