Ta2NiSe5: a candidate topological excitonic insulator with multiple band inversions

Abstract

The electronic structures and topological properties of the orthorhombic and monoclinic phases of the quasi-one-dimensional excitonic insulator Ta2NiSe5 are investigated based on density functional theory. In contrast to a single parity or band inversion across the Fermi level in many topological insulators studied previously, there are multiple parity and band inversions with or without spin-orbit coupling in both phases of Ta2NiSe5, resulting in more complex and topologically nontrivial electronic structures. The Dirac cone type surface states of the low-temperature monoclinic phase are also obtained. In this paper, we demonstrate that Ta2NiSe5 is a promising candidate as a three-dimensional topological excitonic insulator.

28 pages, 11 figures

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Cited by in corpus (2)

• Coalescence of multiple topological orders in quasi-one-dimensional bismuth halide chains
• Electronic and Optical Properties of Ta${}_2$NiSe${}_5$ Monolayer: A First-principles Study