SKM 2023 – wissenschaftliches Programm
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MA: Fachverband Magnetismus
MA 37: Magnetic Heuslers
MA 37.2: Vortrag
Donnerstag, 30. März 2023, 09:45–10:00, HSZ 403
VTaNbAl: A new class of spin gapless semiconductor with topological non-trivial features — •Deepika Rani1, P. C. Sreeparvathy2, K. Gopi Suresh2, Ratnamala Chatterjee1, and Aftab Alam2 — 1Department of Physics, Indian Institute of Technology Delhi, Hauz Khas, New Delhi 110016, India — 2Department of Physics, Indian Institute of Technology Bombay, Mumbai 400076, Maharashtra, India
We report the theoretical prediction of a new class of spin gapless semiconductor (SGS) hosting topological non-trivial features along with a fully compensated ferrimagnetic state in VTaNbAl, a quaternary Heusler alloy. Unlike conventional SGS, this new class of compound acquires a unique band structure with opposite spin characters in the valance and conduction band edges making them potential candidates for spin valves and large anomalous Nernst effect. Interestingly, despite of a compensated ferrimagnetic (CF) behavior, VTaNbAl shows a reasonably large anomalous Hall effect possibly arising from the intrinsic non-vanishing Berry curvature. The CF state breaks the time-reversal symmetry and hence opens the possibility of Weyl nodes. We found four pairs of Weyl nodes located near the Fermi level leading to the non-zero Berry curvature, and hence a large anomalous Hall conductivity (~ 100 S/cm). Our experimental synthesis confirms NbVTaAl to crystallize in a cubic Heusler structure with an A2-type disorder. Magnetization measurement shows a very small saturation moment, which agrees fairly well with our theoretical findings of fully compensated ferrimagnetism in the alloy.