Resistance noise in epitaxial thin films of ferromagnetic topological insulators

Semonti Bhattacharyya, Abhinav Kandala, Anthony Richardella, Saurav Islam, Nitin Samarth, Arindam Ghosh

Research output: Contribution to journalArticle

7 Citations (Scopus)

Abstract

We report detailed temperature and gate-voltage dependence of 1/f resistance noise in magnetically doped topological insulators (TI) Crx(Bi,Sb)2−xTe3. The noise is remarkably sensitive to the gate voltage, increasing rapidly as the chemical potential is moved towards the charge neutrality point. Unlike in identically prepared (Bi,Sb)2Te3 films, where mobility-fluctuations in the surface states is the dominant mechanism, the noise in the magnetic Crx(Bi,Sb)2−xTe3 originates from transport in the localized band tail of the bulk valence band. A strong increase in noise with decreasing temperature supports this scenario. At higher temperature (≥10 K), we observed large noise peaks at gate voltage-dependent characteristic temperature scales. In line with similar observations in other non-magnetic TI systems, we attribute these peaks to generation-recombination in the Cr-impurity band.

Original languageEnglish (US)
Article number082101
JournalApplied Physics Letters
Volume108
Issue number8
DOIs
StatePublished - Feb 22 2016

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insulators
thin films
electric potential
temperature scales
valence
impurities
temperature

All Science Journal Classification (ASJC) codes

  • Physics and Astronomy (miscellaneous)

Cite this

Bhattacharyya, Semonti ; Kandala, Abhinav ; Richardella, Anthony ; Islam, Saurav ; Samarth, Nitin ; Ghosh, Arindam. / Resistance noise in epitaxial thin films of ferromagnetic topological insulators. In: Applied Physics Letters. 2016 ; Vol. 108, No. 8.
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Resistance noise in epitaxial thin films of ferromagnetic topological insulators. / Bhattacharyya, Semonti; Kandala, Abhinav; Richardella, Anthony; Islam, Saurav; Samarth, Nitin; Ghosh, Arindam.

In: Applied Physics Letters, Vol. 108, No. 8, 082101, 22.02.2016.

Research output: Contribution to journalArticle

TY - JOUR

T1 - Resistance noise in epitaxial thin films of ferromagnetic topological insulators

AU - Bhattacharyya, Semonti

AU - Kandala, Abhinav

AU - Richardella, Anthony

AU - Islam, Saurav

AU - Samarth, Nitin

AU - Ghosh, Arindam

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