Galvanomagnetic behavior of hot electrons in semi-insulating GaAs

A new behavior of highly accelerated hot electrons in a magnetic field is observed in semi-insulating GaAs (S.I.GaAs). In an electric field at a few kV/cm, the conduction current in S.I.GaAs increases steeply. The abrupt current increase has been interpreted by the trap-filling model of Lampert. The abrupt current increase shows interesting behavior in a magnetic field. By magnetic field application (at ∼0.3 T), the current increment is cut off. This cutoff behavior requires a new concept of the conduction mechanism in S.I.GaAs. This report suggests that cyclotron cutoff occurs. It implies that the drifting electrons suffer no scattering, just as in vacuum. The scattering relaxation time of an electron is estimated to be extremely long, such as 50 ps.