Optical-Phonon Emission in Ballistic Transport through Microchannels of InGaAs

Abstract

We have observed an oscillatory conductance in electrical transport through In-InGaAs contacts, corresponding to a series of dips in the $I\ensuremath{-}V$ characteristic for both bias polarities at $\mathrm{eV}\ensuremath{\sim}n\ensuremath{\hbar}{\ensuremath{\omega}}_{0}$, where $n$ are integers and $\ensuremath{\hbar}{\ensuremath{\omega}}_{0}$ is the LO-phonon energy of InGaAs. We explain the data by successive LO-phonon emission in high-field transport of ballistic electrons through microchannels of In-GaAs and point out that the experiment is a solid-state analog of the Franck-Hertz experiment.