Abstract
We report that thin films can be epitaxially grown on substrates, which allow for very large tunablity in carrier density with a back gate. The observed low field magnetoconductivity due to weak antilocalization (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 a much suppressed bulk conductivity at large negative gate voltages and a possible role of surface states in the WAL phenomena.
- Received 7 March 2010
DOI:https://doi.org/10.1103/PhysRevLett.105.176602
© 2010 The American Physical Society