WTe2 Topological Insulator: Synthesis, Characterizations and Applications

Since the discovery of a new material phase, topological quantum materials (TQMs), [1] tremendous effort has been made to explore a wide variety of novel and abundant physics appearing in topological insulators (TIs), topological superconductors (TSCs), and Weyl semimetals for creating novel electric and spintronics devices. WTe2 belongs to the family of transition-metal dichalcogenides (TMDs) and crystallizes naturally in a non-centrosymmetric orthorhombic structure (also known as the Td or distorted 1T phase, in which the tungsten atoms are octahedrally coordinated by the tellurium atoms) with polar space group Pmn21. The polar axis in WTe2 is oriented along the stacking direction of layers. Unlike other TMDs, WTe2 is a Weyl semimetal in its native crystal phase [2]. Among Weyl semimetals, Td-type WTe2 is a new class, a type-II Weyl semimetal, where the Weyl points appear at the crossing of the oblique conduction and valence bands due to the broken inversion symmetry and non-saturating giant positive magnetoresistance is a manifestation of the type-II Weyl character [3]. In this presentation the current status of the research and emerging applications of WTe2 are reviewed.<br/> <br/>Acknowledgement: We acknowledge support of the European Union’s Horizon 2020 FET-PROACTIVE project TOCHA under Grant No. 824140<br/> <br/>References<br/>[1] A. A. Soluyanov, D. Gresch, Z. Wang, Q.S. Wu, M. Troyer, X. Dai & A. Bernevig, Nature 527(2015),<br/> pp.495–498<br/>[2] D. Zhang, P. Schoenherr, P. Sharma & J. Seidel, Nature Reviews Materials 8, (2023) pp. 25–40<br/>[3] X.-C. Pan, X. Wang, F. Song & B. Wang Advances in Physics: X, 3, 1, (2018) 1468279