Localization and interaction effects in CdTeBi superlattices

The transport properties of CdTeBi superlattice have been measured as a function of the modulation wavelength. A logarithmic dependence with temperature was observed for the resistance at low temperature. The resistivity varied from 0.1 to 3.9 mΩcm at 1.7 K as the modulation wavelength varied from 177 to 81 A. A logarithmic behavior with H was observed for the transverse (longitudinal) magnetoresistance for low (high) fields. Samples were studied at temperatures down to 1.7 K and in magnetic fields up to 5 Tesla. No negative magnetoresistance as predicted by weak localization theory was observed. Hall coefficient measurements showed a logarithmic dependence with temperature which is indicative of Coulomb correlation effects (interaction theory). All measurements indicate that the transport behavior of CdTeBi superlattices is dominated by spin-orbit and/or interaction effects while weak localization plays a minimal role.