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Electric transport and low-frequency noise characterization of $Bi_{2}Se_{3}$ topological insulator thin films.
Barone C., Orgiani P., Carapella G., Granata V., Chaluvadi S.K., Pagano S.
New states of quantum matter, not directly related to conventional insulators and semiconductors, are represented by topological insulators. Due to a strong contribution of the surface to transport, these compounds have attracted an increasing interest. In order to better investigate the effect of intrinsic fluctuations on the surface conduction, a detailed characterization of the low-frequency noise has been made on $Bi_{2}Se_{3}$ thin films. The experiments have been performed by varying the samples thickness and geometry, in a temperature range from 300 down to 8 K, and as a function of dc bias current and gate voltage. The obtained results have shown standard thermal and shot noise contributions, while an unusual reduction of the $1/f$ noise component has been found. This behavior, especially evident in the low-temperature region, has been correlated with structural and dc electric transport properties. From the observations reported, a clear indication on the occurrence of the topological regime has been observed. Therefore, flicker noise measurement is a valid alternative technique to standard topological surface state spectroscopy.