Impact ionization and large room-temperature magnetoresistance in micron-sized high-mobility InAs channels

Abstract

We report on hot electron induced impact ionization and large room-temperature magnetoresistance (MR) in micron-sized channels of $n$-type high-mobility InAs $(\ensuremath{\mu}=3.3{\mathrm{m}}^{2}{\mathrm{V}}^{\ensuremath{-}1}{\mathrm{s}}^{\ensuremath{-}1}$ at $T=300\mathrm{K})$: the MR reaches values of up to 450% in magnetic fields of 1 T and applied voltages of \ensuremath{\sim}1 V and is weakly dependent on temperature. We present Monte Carlo simulations of the hot electron dynamics to account for the large MR and its dependence on the sample geometry and applied electric and magnetic fields. Our work demonstrates that the impact ionization of electrons at room temperature, under small applied magnetic fields (1 T) and small voltages (1 V), can provide an extremely sensitive mechanism for controlling the electrical resistance of high-mobility semiconductors.