Banerjee, Abhishek and Deb, Oindrila and Majhi, Kunjalata and Ganesan, R and Sen, Diptiman and Anil Kumar, PS (2017) Granular topological insulators. In: Nanoscale, 9 (20). pp. 6755-6764. ISSN 2040-3364
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Abstract
We demonstrate experimentally that a macroscopic topological insulator (TI) phase can emerge in a granular conductor composed of an assembly of tunnel coupled TI nanocrystals of dimension ∼10 nm × 10 nm × 2 nm. Electrical transport measurements on thin films of Bi2Se3 nanocrystals reveal the presence of decoupled top and bottom topological surface states that exhibit large surface state penetration depths (∼30 nm at 2 K). By tuning the size of the nanocrystals and the couplings between them, this new class of TIs may be readily tuned from a non-topological to a topological insulator phase, that too with designer properties. Paradoxically, this seemingly 'dirty' system displays properties that are closer to an ideal TI than most known single crystal systems, making granular/nanocrystalline TIs an attractive platform for future TI research.
| Item Type: | Journal Article |
|---|---|
| Publication: | Nanoscale |
| Publisher: | Royal Society of Chemistry |
| Additional Information: | The Copyright of this article belongs to the Authors. |
| Keywords: | Electric insulators; Nanocrystals; Surface states; Crystal system; Electrical transport measurements; Large surfaces; System displays; Topological insulators; Topology |
| Department/Centre: | Division of Physical & Mathematical Sciences > Centre for High Energy Physics Division of Physical & Mathematical Sciences > Physics |
| Date Deposited: | 02 Jun 2022 04:54 |
| Last Modified: | 02 Jun 2022 04:55 |
| URI: | https://eprints.iisc.ac.in/id/eprint/72979 |
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