Magnetotransport and high-resolution angle-resolved photoelectron spectroscopy studies of palladium-doped Bi2Te3

We have performed magnetotransport and high-resolution angle-resolved photoelectron spectroscopy (ARPES) measurements on topological insulator PdxBi2Te3 (0 <= x <= 0.20) single crystals. We have observed unusually high values of magnetoresistance (similar to 1500%) and mobility (similar to 93 000 cm(2) V-1 s(-1)) at low temperatures for pristine Bi2Te3 that decrease upon Pd doping. Shubnikov-de Haas (SdH) oscillations were detected for x = 0.05, 0.10, confirming the presence of two-dimensional topological surface states (TSSs) for these samples. Hall measurement shows the crossover from n-type charge carriers in pristine Bi2Te3 to p-type charge carriers upon Pd doping. The ARPES measurements show that the conduction band crosses the Fermi level for pristine Bi2Te3, and the Dirac point of the TSSs and bulk-derived valence bands indicated a shift to lower binding energy upon Pd doping in a rigid-band-like way up to x similar to 0.10. Based on the comparison of the parameters obtained from the SdH and ARPES measurements, the reduction in the k(F) value in the magnetotransport measurements is likely due to the band bending induced by the Schottky barrier.

Automated summary

The researchers conducted magnetotransport and ARPES measurements on PdxBi2Te3 single crystals and discovered the reduction of magnetoresistance and mobility upon Pd doping, as well as the presence of TSSs confirmed by SdH oscillations. Hall measurement and ARPES measurements also revealed the change in charge carrier type and band structure induced by Pd doping.