Measurement of the Band-Structure Effective Mass and Application to the Electron-Phonon Interaction in Indium

Abstract

Measurements are reported of the rate of change of the third-band Fermi-surface principal cross-sectional area in indium doped with up to 2% cadmium. The interpretation, with small corrections due to changes in the alloy band gaps, gives an experimental determination of the band mass $m_B$ in excellent agreement with Ashcroft's local-pseudopotential value. An estimate of the electron-phonon mass-enhancement factor for this band of $1+\lambda =1.95\mathrm{}\pm 0.11$ follows from comparison with the measured cyclotron mass. This value exceeds the average value $1+\lambda =1.69\mathrm{}$ derived from tunneling measurements, and the anisotropy provides independent support for Ashcroft's choice between two competing band structures for indium.