Metal - insulator transition in Sb-doped short-period Si/SiGe superlattices

Symmetrically strained Si/SiGe superlattices (25 Å wells/14 Å barriers) with homogeneous Sb doping concentrations of 4.5 and show low-temperature magnetoconductivity effects which can be explained by single-electron backscattering and disorder-induced electron - electron interaction for an anisotropic three-dimensional case. The insulating phase of two lower doped samples (2.0 and ) is documented by the observation of variable range hopping conductivity. In addition, the extrapolated zero-temperature conductivities for in different magnetic fields show a magnetic-field-induced metal-to-insulator transition, demonstrating a three-dimensional behaviour of this superlattice with respect to localization.