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MM: Fachverband Metall- und Materialphysik

MM 14: Development of Computational Methods: Thermodynamics and Local Chemistry, Electronic Structure

MM 14.6: Vortrag

Dienstag, 28. März 2023, 11:45–12:00, SCH A 251

Pressure-driven tunable properties of the small-gap chalcopyrite topological quantum material ZnGeSb2: A first-principles study — •Surasree Sadhukhan¹, Banasree Sadhukhan², and Sudipta Kanungo¹ — ¹Indian Institute of Technology Goa, 403401 Ponda, India — ²KTH Royal Institute of Technology, Stockholm

Search for new topological quantum materials is the demand to achieve substantial growth topological phase of matter. In this search process, theoretical prediction is crucial besides the obvious experimental verification. The divination of topological properties in already well-known narrow gap semiconductors is flourishing in quantum material science. We revisited the semiconductor compound in the chalcopyrite series, some of which were potential topological materials. Using this density functional theory-based first-principles calculations, we report a strong topologically nontrivial phase in chalcopyrite ZnGeSb 2, which can act as a model system of strained HgTe. The estimates reveal the non-zero topological invariant (Z 2 ), Dirac cone crossing in the surface spectral functions with spin-momentum locked spin texture. We also report the tunable topological properties from nontrivial to trivial phases under moderate hydrostatic pressure within *7 GPa. A minor modification of a lattice parameter is enough to achieve this topological phase transition easily accomplished in an experimental lab. We have incorporated the discontinuity in the tetragonal distortion of non-centrosymmetric ZnGeSb 2 to drive the topological quantum phase transition.