We report that Bi2Se3 thin films can be epitaxially grown on SrTiO3 substrates, which allow for very large tunablity in carrier density with a back-gate. The observed low field magnetoconductivity due to weak anti-localization (WAL) has a very weak gate-voltage dependence unless the electron density is reduced to very low values. Such a transition in WAL is correlated with unusual changes in longitudinal and Hall resistivities. Our results suggest much suppressed bulk conductivity at large negative gate-voltages and a possible role of surface states in the WAL phenomena. This work may pave a way for realizing three-dimensional topological insulators at ambient conditions.
@article{arxiv.1003.1534,
title = {Gate-Voltage Control of Chemical Potential and Weak Anti-localization in Bismuth Selenide},
author = {J. Chen and H. J. Qin and F. Yang and J. Liu and T. Guan and F. M. Qu and G. H. Zhang and J. R. Shi and X. C. Xie and C. L. Yang and K. H. Wu and Y. Q. Li and L. Lu},
journal= {arXiv preprint arXiv:1003.1534},
year = {2010}
}