Observation of π Berry phase in quantum oscillations of three‐dimensional Fermi surface in topological insulator Bi2Se3. Issue 11 (6th October 2015)

• Record Type: Journal Article
• Authors: Kumar, Devendra; Lakhani, Archana
• Is Part Of: Physica status solidi. Volume 9:Issue 11(2015:Nov.)
• Page Start: 636
• Page End: 640
• Publication Date: 2015-10-06
• Subjects: topological insulators -- Bi2Se3 -- Dirac fermions -- Berry phase -- Shubnikov−de Haas oscillations; Solid state physics -- Periodicals; 530.4105
• DOI: 10.1002/pssr.201510260
• Languages: English
• ISSNs: 1862-6254

Abstract

Abstract : We report the quantum transport studies on Bi2 Se3 single crystal with bulk carrier concentration of ∼10 19 cm –3 . The Bi2 Se3 crystal exhibits metallic character, and at low temperatures, the field dependence of resistivity shows clear Shubnikov–de Haas (SdH) oscillations above 6 T. The analysis of these oscillations through Lifshitz–Kosevich theory reveals a non‐trivial π Berry phase coming from three‐dimensional (3D) Fermi surface, which is a strong signature of Dirac fermions with three‐dimensional dispersion. The large Dingle temperature and non zero slope of Williamson–Hall plot suggest the presence of enhanced local strain field in our system which possibly transforms the regions of topological insulator to 3D Dirac fermion metal state. (© 2015 WILEY‐VCH Verlag GmbH &Co. KGaA, Weinheim) Abstract : This Letter reports the observation of π Berry phase in Shubnikov–de Haas oscillations of bulk states of a Bi2 Se3 crystal having microstrain. The transformation of Bi2 Se3 crystal regions from topological to 3D Dirac fermion metal state due to the presence of enhanced local strain field is demonstrated.