Temperature-driven spin-zero effect in TaAs2. (November 2022)

• Record Type: Journal Article
• Authors: Alam, Md. Shahin; Tanwar, P.K.; Dybko, Krzysztof; Wadge, Ashutosh S.; Iwanowski, Przemysław; Wiśniewski, Andrzej; Matusiak, Marcin
• Is Part Of: Journal of physics and chemistry of solids. Volume 170(2022)
• Publication Date: 2022-11
• Subjects: Topological semimetals -- Nernst effect -- Quantum oscillations -- Spin-zero effect; Solids -- Periodicals; Solides -- Périodiques; Solids; Periodicals; 530.41
• DOI: 10.1016/j.jpcs.2022.110939
• Languages: English
• ISSNs: 0022-3697

Abstract

Abstract: The electrical and thermo-electrical transport properties of the semimetal TaAs2 have been measured in a magnetic field applied along the [−2 0 1] direction. The resulting field dependences of the resistivity as well as the Hall, Seebeck, and Nernst coefficients below T ≈ 100 K can be satisfactorily described within the two-band model consisting of electron and hole pockets. At low temperature, all of the measured coefficients exhibit significant contributions from quantum oscillations. The fast Fourier-transform (FFT) of the oscillatory Nernst signal shows two fundamental frequencies, F α = 105 T and F β = 221 T, and the second harmonic of the latter ( F 2β = 442 T). The ratio between the FFT amplitudes of F β and F 2β changes with temperature in an unusual way, indicating the observation of a spin-zero effect caused by temperature change. This is likely related to the substantial temperature dependence of the Landé g -factor, which in turn may stem from the non-parabolic energy dispersion or temperature evolution of the spin-orbit coupling. Highlights: TaAs2, a potentially new type of a topological semimetal, is studied. T - and B -dependences of the magneto-thermo-electrical effects were measured. Remarkable behaviour of the quantum oscillations amplitude was observed. The results are interpreted in terms of the spin-zero effect. Data may indicate a profound change of the topological attributes.