Discovery of highly spin-polarized conducting surface states in the strong spin-orbit coupling semiconductor Sb2Se3

Das, Shekhar and Sirohi, Anshu and Gupta, Gaurav Kumar and Kamboj, Suman and Vasdev, Aastha and Gayen, Sirshendu and Guptasarma, Prasenjit and Das, Tanmoy and Sheet, Goutam (2018) Discovery of highly spin-polarized conducting surface states in the strong spin-orbit coupling semiconductor Sb2Se3. In: PHYSICAL REVIEW B, 97 (23).

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Abstract

Majority of the A(2)B(3)-type chalcogenide systems with strong spin-orbit coupling (SOC), such as Bi2Se3, Bi2Te3, and Sb2Te3, etc., are topological insulators. One important exception is Sb2Se3 where a topological nontrivial phase was argued to be possible under ambient conditions, but such a phase could be detected to exist only under pressure. In this paper, we show that Sb2Se3 like Bi2Se3 displays a generation of highly spin-polarized current under mesoscopic superconducting point contacts as measured by point-contact Andreev reflection spectroscopy. In addition, we observe a large negative and anisotropic magnetoresistance of the mesoscopic metallic point contacts formed on Sb2Se3. Our band-structure calculations confirm the trivial nature of Sb2Se3 crystals and reveal two trivial surface states one of which shows large spin splitting due to Rashba-type SOC. The observed high spin polarization and related phenomena in Sb2Se3 can be attributed to this spin splitting.

Item Type:	Journal Article
Publication:	PHYSICAL REVIEW B
Publisher:	AMER PHYSICAL SOC, ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA
Additional Information:	Copy right of this article belong to AMER PHYSICAL SOC, ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA
Department/Centre:	Division of Interdisciplinary Sciences > Supercomputer Education & Research Centre Division of Physical & Mathematical Sciences > Physics
Date Deposited:	25 Jun 2018 15:53
Last Modified:	25 Jun 2018 15:53
URI:	http://eprints.iisc.ac.in/id/eprint/60080

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