Observation of Dirac-like surface state bands on the top surface of BiSe

Lohani, H and Majhi, K and Ganesan, R and Gonzalez, S and Di Santo, G and Petaccia, L and Anil Kumar, PS and Sekhar, BR (2021) Observation of Dirac-like surface state bands on the top surface of BiSe. In: EPL, 134 (2).

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Abstract

Weak topological insulators (TIs) host non-trivial topological surface state bands (SSBs) at the side surface of the crystal while the top (001) surface can be topologically either dark or light. In our detailed angle-resolved photoelectron spectroscopy (ARPES) study we found Dirac-like linearly dispersive SSBs on the (001) surface of BiSe and Sb-doped (8) BiSe. The lower part of the SSBs buries deep in the bulk valence band (BVB) and the overlap region between the SSBs and BVB increases significantly with Sb doping. These results highlight the role of the interlayer coupling between the Bi bilayer and the Bi2Se3 quintuple layer (QL). Furthermore, in the overlap region the SSBs deviate from the Dirac-like linear dispersion. Interestingly, we observed a large intensity imbalance I(k||) â� I(â��k||) in the SSBs located at the positive and negative k|| directions. This asymmetry pattern I(k||) > I(â��k||) gradually reverses to I(k||) < I(â��k||) as the excitation energy scans from low (14 eV) to high (34 eV) values. The observed photon energy-dependent intensity variation could be a signature of the mixing between the spin and the orbit texture of the SSBs. Copyright © 2021 EPLA

Item Type:	Journal Article
Publication:	EPL
Publisher:	IOP Publishing Ltd
Additional Information:	The copyright for this article belongs to IOP Publishing Ltd
Department/Centre:	Division of Physical & Mathematical Sciences > Physics
Date Deposited:	25 Aug 2021 10:29
Last Modified:	25 Aug 2021 10:29
URI:	http://eprints.iisc.ac.in/id/eprint/69344

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