| Abstract: | Landau-level lifetimes are determined from saturation cyclotron resonance (CR) in wide parabolic wells, quantum wells and bulk PbTe–Pb1−xEuxTe systems. These narrow gap structures exhibit strong band non-parabolicity necessary to terminate the normally equi-spaced Landau-level ladder. It was not possible to saturate the bulk sample, but short lifetimes, of between 1.5 and 8 ps, were obtained for the wide parabolic well and the quantum well, respectively, utilising a multi-level rate equation model. We also report the first pump–probe cyclotron resonance result in an InAs–AlSb quantum structure. The pump–probe experiment provides a direct determination of the lifetime, giving τ=40 ps in this InAs–AlSb sample. This shows good agreement with an 8×8k·p calculation. |
