Hot electron magnetotransport in the high mobility GaAs/AlGaAs two dimensional electron system below 1K

Non-equilibrium hot electron phenomena play a major role in semiconductor transport when, for example, the heat applied directly to the electronic system becomes substantial. The carrier temperature can differ from the lattice temperature, and the carrier temperature results, in the steady state, from a balance between energy gain from the heating source, and energy loss to the lattice from electron-phonon scattering. In this experimental study, we examine heating induced by the small ac-bias current utilized in the low-frequency lock-in based four terminal transport measurements. Since at small bias current, the carrier heating is expected to be small, we have utilized an effect that is associated with a small energy scale to follow the heating effect, namely the spin splitting in the Shubnikov-de Haas effect. The development of fields such as spintronics and spin-based quantum computing have encouraged further studies, such as this one, of the parameters affecting the behavior of electron spin in low dimensional electron systems. Thus, magneto-transport measurements have been carried out below 1K to observe the ac current effect on the characteristic features of the GaAs/AlGaAs system. In this report, we show evidence for a carrier heating effect due to the small ac bias.