Band Structure of Topological Insulator BiSbTe1.25Se1.75

Lohani, H and Mishra, P and Banerjee, A and Majhi, K and Ganesan, R and Manju, U and Topwal, D and Kumar, P S Anil and Sekhar, B R (2017) Band Structure of Topological Insulator BiSbTe1.25Se1.75. In: SCIENTIFIC REPORTS, 7 .

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Abstract

We present our angle resolved photoelectron spectroscopy (ARPES) and density functional theory results on quaternary topological insulator (TI) BiSbTe1.25Se1.75 (BSTS) confirming the non- trivial topology of the surface state bands (SSBs) in this compound. We find that the SSBs, which are are sensitive to the atomic composition of the terminating surface have a partial 3D character. Our detailed study of the band bending (BB) effects shows that in BSTS the Dirac point (DP) shifts by more than two times compared to that in Bi2Se3 to reach the saturation. The stronger BB in BSTS could be due to the difference in screening of the surface charges. From momentum density curves (MDCs) of the ARPES data we obtained an energy dispersion relation showing the warping strength of the Fermi surface in BSTS to be intermediate between those found in Bi2Se3 and Bi2Te3 and also to be tunable by controlling the ratio of chalcogen/pnictogen atoms. Our experiments also reveal that the nature of the BB effects are highly sensitive to the exposure of the fresh surface to various gas species. These findings have important implications in the tuning of DP in TIs for technological applications.

Item Type:	Journal Article
Publication:	SCIENTIFIC REPORTS
Publisher:	NATURE PUBLISHING GROUP, MACMILLAN BUILDING, 4 CRINAN ST, LONDON N1 9XW, ENGLAND
Additional Information:	Copy right for the article belong to NATURE PUBLISHING GROUP, MACMILLAN BUILDING, 4 CRINAN ST, LONDON N1 9XW, ENGLAND
Department/Centre:	Division of Physical & Mathematical Sciences > Physics
Date Deposited:	14 Mar 2018 17:38
Last Modified:	14 Mar 2018 17:38
URI:	http://eprints.iisc.ac.in/id/eprint/59186

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