Exceptional Topological Insulators

Topological INsulators

Researchers from the group Neupert propose the non-Hermitian analogue of three-dimensional topological insulators.

Three-dimensional topological insulators have become a research focal point on topological quantum matter. A recent work led by the group of Titus Neupert now proposes an analogue in dissipative systems, which are described by non-Hermitian operators, the exceptional topological insulator (ETI). Like normal topological insulators, the ETI hosts exotic surface states. Mathematically, they have a band structure with a so-called exceptional point, which can only exist because of the 3D topological bulk embedding. Such a phase could for instance describe the physics of quasiparticles in Weyl semimetals with strong electron-phonon interaction.
Nature Communications 12, 5681 (2021)

Katharina Müller