Evidence for topological semimetallicity in a chain-compound TaSe3

• Published in: npj quantum materials 2020-07, Vol.5 (1), Article 53
• Main Authors: Saleheen, Ahmad Ikhwan Us, Chapai, Ramakanta, Xing, Lingyi, Nepal, Roshan, Gong, Dongliang, Gui, Xin, Xie, Weiwei, Young, David P., Plummer, E. W., Jin, Rongying
• Format: Article
• Language: English
• Subjects: 639/301/119/2792/4128; 639/766/119/2792; 639/766/119/995; Condensed Matter Physics; CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY; Electrical resistivity; Electronic properties; Electronic properties and materials; First principles; Magnetoresistance; Magnetoresistivity; Mathematical analysis; Metallicity; Physics; Physics and Astronomy; Quantum Physics; Residual resistivity; Resistivity ratio; Single crystals; Structural Materials; Surfaces and Interfaces; Thin Films; Topological insulators; Topological matter; Topology; Transition metals
• ISSN: 2397-4648; 2397-4648
• DOI: 10.1038/s41535-020-00257-7

Among one-dimensional transition-metal trichalcogenides, TaSe 3 is unconventional in many respects. One is its strong topological semimetallicity as predicted by first-principles calculations. We report the experimental investigations of the electronic properties of one-dimensional-like TaSe 3 single crystals. While the b -axis electrical resistivity shows good metallicity with a high residual resistivity ratio greater than 100, an extremely large magnetoresistance is observed reaching ≈7 × 10 3 % at 1.9 K for 14 T. Interestingly, the magnetoresistance follows the Kohler’s rule with nearly quadratic magnetic field dependence, consistent with the electron–hole compensation scenario as confirmed by our Hall conductivity data. Both the longitudinal and Hall conductivities show Shubnikov-de Haas oscillations with two frequencies: F α  ≈ 97 T and F β  ≈ 186 T. Quantitative analysis indicates that F α results from the two-dimensional-like electron band with the non-trivial Berry phase [1.1 π ], and F β from the hole band with the trivial Berry phase [0(3D) − 0.16 π (2D)]. Our experimental findings are consistent with the predictions based on first-principles calculations.