Transport scattering time and single-particle relaxation time in ZnO/MgZnO heterostructures: Many-body effects.

Recent experimental results regarding the transport properties of ZnO/MgZnO heterostructures with very high mobility (μ≤1.8×10⁵cm²/Vs) are analyzed. In the electron density range of the experiment, the two-dimensional electron gas in ZnO/MgZnO heterostructures is strongly correlated with a large Wigner-Seitz parameter 4 < rs < 12. We demonstrate that many-body effects (exchange and correlation), described by a local-field correction, are very large in this density range. They reduce the screening properties of the two-dimensional electron gas and strongly reduce the transport scattering time and the single-particle relaxation time at low electron densities. For such samples, we also discuss the peak mobility, the metal-insulator transition, and the magnetoresistance in a parallel magnetic field. [ABSTRACT FROM AUTHOR]