Anomalous Magneto-Transport Properties of Epitaxial Single-Crystal Bi Films on Si（111）

Anomalous transport properties of 40-nm-thick single-crystal Bi（111） films grown on Si（111）-7 × 7 substrates is investigated. The magnetoresistance （MR） of the films in perpendicular magnetic field shows a regular positive behavior in the temperature range 2–300K, the MR in parallel field （B｜｜） displays a series of interesting features. Specifically, we observe a change of the MR （B｜｜） behavior from positive to negative when the temperature is below 10K. In the range 10–170 K, the MR （B｜｜） is negative in the investigated field of 9T. When T 〉 170 K, a positive MR appears in the high field regime. The low temperature MR（B｜｜） behavior in the parallel field can be understood by the competition between weak localization and weak anti-localization （WAL）. Furthermore, our results suggest that the WAL is dominated by the interface carriers.

Anomalous Magneto-Transport Properties of Epitaxial Single-Crystal Bi Films on Si(111)