Observation of the Weak Antilocalization and Linear Magnetoresistance in Topological Insulator Thin Film Hall Bar Device

Abstract

In this research work, without using any resist and lithography techniques, we report clean, surface protected and high quality Topological Insulator (TI) thin film Hall Bar device of millimeter size long. In the magnetotransport measurements, the pronounced effect of weak antilocalization (WAL) behavior has been observed at low temperatures over the range T = 4-10 K and in the low field regions and the WAL cusp disappears as we go from 10 K onwards to higher temperatures, also we find that the high-field magenetoresistance (MR) is linear in field. With respect to magnetic field (B), the MR behavior seems to be symmetric. We also analyze the thickness dependent weak antilocalization (WAL) behavior, which has been observed in Topological Insulator Bi Te 3 thin film Hall Bar device. For varying thickness, our systematic magnetotransport measurements reveal WAL signals obtain in thicker films whereas below the critical thickness of ~4 nm, a sudden diminishment of the surface transport has been observed by suppression of WAL behavior. The analyzed and pronounced behavior of this effect is also greatly dependent on the temperatures, where the WAL cusps are observed in the low-field regions and at low temperatures.