Observation of the magneto-transport property in a millimeter-long topological insulator Bi 2 Te 3 thin-film Hall bar device

Abstract In this work, we report clean, surface protected and high quality topological insulator (TI) thin film Hall bar device of millimeter size long, without using any resist and lithography techniques. The pronounced effect of weak anti-localization (WAL) behavior has been observed in the magneto-transport measurements at low temperatures over the range T = 4–10 K and in the low field regions and as we go from 10 K onwards to higher temperatures the WAL cusp disappears, also we find that the high field magenetoresistance (MR) is linear in field. The MR behavior with respect to magnetic field (B) seems to be symmetric. We also report thickness dependent weak-anti localization (WAL) behavior in topological insulator Bi 2 Te 3 thin film Hall bar device. Our systematic magneto-transport measurements for varying thickness reveal WAL signals obtain in thicker films, where as a sudden diminishment of the surface transport below the critical thickness of ∼4 nm has been observed by suppression of WAL behavior. The pronounced behavior of this effect is also found to be dependent on the temperatures, where the WAL cusps are observed at low temperatures in the low-field regions.