Signature of pseudodiffusive transport in mesoscopic topological insulators

Islam, S and Bhattacharyya, S and Nhalil, H and Elizabeth, S and Ghosh, A (2020) Signature of pseudodiffusive transport in mesoscopic topological insulators. In: Physical Review Research, 2 (3).

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Abstract

One of the unique features of Dirac Fermions is pseudodiffusive transport by evanescent modes at low Fermi energies when disorder is low. At higher Fermi energies, i.e., charge carrier densities, the electrical transport is diffusive in nature and the propagation occurs via plane waves. In this study, we report the detection of such evanescent modes in the surface states of topological insulator through 1/f noise for the first time. While signatures of pseudodiffusive transport have been seen experimentally in graphene, such behavior is yet to be observed explicitly in any other system with a Dirac dispersion. To probe this, we have studied 1/f noise in topological insulators as a function of gate voltage, and temperature. Our results show a nonmonotonic behavior in 1/f noise as the gate voltage is varied, suggesting a crossover from pseudodiffusive to diffusive transport regime in mesoscopic topological insulators. The temperature dependence of noise points towards conductance fluctuations from quantum interference as the dominant source of the noise in these samples. © 2020 authors. Published by the American Physical Society. Published by the American Physical Society under the terms of the Creative Commons Attribution 4.0 International license. Further distribution of this work must maintain attribution to the author(s) and the published article's title, journal citation, and DOI.

Item Type:	Journal Article
Publication:	Physical Review Research
Publisher:	American Physical Society
Additional Information:	The copyright for this article belongs to the American Physical Society
Keywords:	Superconducting materials; Temperature distribution; Threshold voltage; Topological insulators, Conductance fluctuation; Diffusive transport regime; Electrical transport; Evanescent mode; Nonmonotonic behaviors; Quantum interference; Temperature dependence; Unique features, Electric insulators
Department/Centre:	Division of Interdisciplinary Sciences > Centre for Nano Science and Engineering Division of Physical & Mathematical Sciences > Physics
Date Deposited:	28 Nov 2021 10:04
Last Modified:	28 Nov 2021 10:04
URI:	http://eprints.iisc.ac.in/id/eprint/70320

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