Topological behavior and Zeeman splitting in trigonal PtBi2-x single crystals

• Published in: npj quantum materials 2020-02, Vol.5 (1), Article 10
• Main Authors: Xing, Lingyi, Chapai, Ramakanta, Nepal, Roshan, Jin, Rongying
• Format: Article
• Language: English
• Subjects: 639/301/119/2792; 639/301/119/995; CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSICS; Condensed Matter Physics; Crystal structure; Fast Fourier transformations; Low temperature; Magnetic properties; Magnetoresistance; Magnetoresistivity; MATERIALS SCIENCE; Oscillations; Physical properties; Physics; Physics and Astronomy; Quantum Physics; Single crystals; Splitting; Structural Materials; Surfaces and Interfaces; Thin Films; Topology; Transition metals; Zeeman effect
• ISSN: 2397-4648; 2397-4648
• DOI: 10.1038/s41535-020-0213-9

Transition-metal dipnictide PtBi 2 exhibits rich structural and physical properties with topological semimetallic behavior and extremely large magnetoresistance (XMR) at low temperatures. We have investigated the electrical and magnetic properties of trigonal-phase PtBi 2 -x single crystals with x  ~ 0.4. Profound de Haas–van Alphen (dHvA) and Shubnikov-de Haas (SdH) oscillations are observed. Through fast Fourier transformation (FFT) analyses, four oscillation frequencies are extracted, which result from α, β, γ, and δ bands. By constructing the Landau fan diagram for each band, the Berry phase is extracted demonstrating the non-trivial nature of the α, β, and δ bands. Despite Bi deficiency, we observe the Zeeman splitting in dHvA and SdH oscillations under moderate magnetic field and the moderate Landé g factor (4.97–6.48) for the α band. Quantitative analysis of the non-monotonic field dependence including the sign change of the Hall resistivity suggests that electrons and holes in our system are not perfectly compensated thus not responsible for the XMR effect.