We report low-temperature far-infrared magneto-optical measurements on a remotely doped, asymmetric, wide parabolic AlxGa1-xAs quantum well with two curvatures. The collective cyclotron-resonance spectrum of the system, measured with an in-plane magnetic field, is found to depend on the electron areal density Ns. At sufficiently high Ns, so that the effective layer thickness is much larger than the magnetic length, two plasma frequencies associated with the two curvatures are observed, showing that the system behaves as a classical, inhomogeneous, three-dimensional electron plasma. At low Ns, only one resonance is observed, corresponding to the lowest optical transition between the quantized levels in the nearly empty well.
All Science Journal Classification (ASJC) codes
- Condensed Matter Physics