Narrowing of cyclotron resonance lines in InSb at far-infrared laser frequencies☆

Abstract Cyclotron resonance lines in n -type InSb at 4.2K are observed to narrow as the resonant magnetic field is increased. A line shape analysis at λ = 337, 118.6 and 78.4 microm yields an electron-impurity scattering time τ greatly in excess of the one calculated from d.c. mobility measurements.