Year: 2012
Type: article
Abstract: With high quality topological insulator ${\mathrm{Bi}}_{2}{\mathrm{Se}}_{3}$ thin films, we report thickness-independent transport properties over wide thickness ranges. Conductance remained nominally constant as the sample thickness changed from 256 to $\ensuremath{\sim}8\text{ }\text{ }\mathrm{QL}$ (where QL refers to quintuple layer, $1\text{ }\text{ }\mathrm{QL}\ensuremath{\approx}1\text{ }\text{ }\mathrm{nm}$). Two surface channels of very different behaviors were identified. The sheet carrier density of one channel remained constant at $\ensuremath{\sim}3.0\ifmmode\times\else\texttimes\fi{}{10}^{13}\text{ }\text{ }{\mathrm{cm}}^{\ensuremath{-}2}$ down to 2 QL, while the other, which exhibited quantum oscillations, remained constant at $\ensuremath{\sim}8\ifmmode\times\else\texttimes\fi{}{10}^{12}\text{ }\text{ }{\mathrm{cm}}^{\ensuremath{-}2}$ only down to $\ensuremath{\sim}8\text{ }\text{ }\mathrm{QL}$. The weak antilocalization parameters also exhibited similar thickness independence. These two channels are most consistent with the topological surface states and the surface accumulation layers, respectively.
Source: Physical Review Letters
Language: English
Subfield: Condensed Matter Physics
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: green
OpenAlex ID: W2014641563