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arXiv · 2112.10455

Bad topological semimetals in layered honeycomb compounds

Manuel Fernández López·Jaime Merino
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Abstract

The Mott transition in honeycomb compounds with significant spin-orbit coupling is explored. At finite temperatures we identify a novel semimetallic phase located between a topological insulator and a topological Mott insulator. This semimetal is characterized by having no charge gap, no quasiparticles and gapped spin excitations with non-trivial topological properties. While charge conduction is incoherent involving mean-free paths violating the Mott-Ioffe-Regel limit, spin excitations can be transported ballistically along the edges giving rise to a quantized spin conductance. Such bad topological semimetal could be searched for close to the Mott transition in certain twisted bilayers of transition metal dicalchogenides.

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Manuel Fernández López, Jaime Merino. 2021-12-20. Bad topological semimetals in layered honeycomb compounds. https://doi.org/10.1103/physrevb.105.115138

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