Investigation of Angle‐Dependent Shubnikov‐de Haas Oscillations in Topological Insulator Bismuth

• Published in: physica status solidi (b) 2025-01, Vol.262 (1), p.n/a
• Main Authors: Karn, Navneet Kumar, Kumar, Yogesh, Awana, Geet, Awana, Veer Pal Singh
• Format: Article
• Language: English
• Subjects: Berry's phase; Landau level index; magnetoresistance; Shubnikov-de Haas oscillations; single crystal; Z2 invariant
• ISSN: 0370-1972; 1521-3951
• DOI: 10.1002/pssb.202400077

The current article investigates the band structure in the presence and absence of spin‐orbit coupling (SOC), examines the Z2 invariants, and investigates the detailed angle‐dependent magneto‐transport of up to 10 T (Tesla) and down to 2 K for the bismuth crystal. The out‐of‐plane field‐dependent magnetoresistance (MR) is positive and is huge to the order of ≈104% at 2 K and 10 T. On the contrary, the longitudinal (in‐plane) field‐dependent MR is relatively small and is negative. The thermal activation energy is also estimated by using the Boltzmann formula from resistivity versus temperature measurement under applied transverse magnetic fields. The topological nature of Bi is confirmed by Z2 invariant calculation using density functional theory (DFT). PBESol bands show trivial but hybrid functional (HSE) bands show non‐trivial topology being present in Bismuth. This article comprehensively studies the dependence of MR oscillations upon the angle between the applied field and the current. The observed oscillations fade away as the angle is increased. This article is an extension of our previous work on bismuth (J. Sup. Novel Mag. 2023, 36, 389), in which a comprehensive analysis of its structural and micro‐structural properties is conducted along with its transport behavior in an applied transverse magnetic field. This article reports angle‐dependent magneto‐transport properties of synthesized single crystal of bismuth. Shubnikov de Haas oscillations are observed at different angles. The non‐trivial topological character of Bi is shown by calculating π Berry phase using LL fan diagram. The same is confirmed by calculating the Z2 invariant using the first principle method.