Symmetry indicators for inversion-symmetric non-Hermitian topological band structures

Topological Insulators with Inversion Symmetry

Topological insulators are materials with a bulk excitation gap generated by the spin-orbit interaction that are different from conventional insulators. This distinction is characterized by Z2 topological invariants, which characterize the ground state. In two dimensions, there is a single Z2 invariant that distinguishes the ordinary insulator from the quantum spin-Hall phase. In three dimensio...

Harmonic Morphisms, Hermitian Structures and Symmetric Spaces

[A] M. Svensson, On holomorphic harmonic morphisms, Manuscripta Math. 107 (2002), 1–13. [B] M. Svensson, Harmonic morphisms from even-dimensional hyperbolic spaces, Math. Scand. 92 (2003), 246–260. [C] M. Svensson, Holomorphic foliations, harmonic morphisms and the Walczak formula, J. London Math. Soc. 68 (2003), 781–794. [D] M. Svensson, Harmonic morphisms in Hermitian geometry, J. Reine Angew...

Computing topological invariants without inversion symmetry

We consider the problem of calculating the weak and strong topological indices in noncentrosymmetric time-reversal (T ) invariant insulators. In 2D we use a gauge corresponding to hybrid Wannier functions that are maximally localized in one dimension. Although this gauge is not smoothly defined on the two torus, it respects the T symmetry of the system and allows for a definition of the Z2 inva...

Topological Nonsymmorphic Metals from Band Inversion

Lukas Muechler, A. Alexandradinata, Titus Neupert, and Roberto Car Department of Chemistry, Princeton University, Princeton, New Jersey 08544, USA Department of Physics, Yale University, New Haven, Connecticut 06520, USA Department of Physics, Princeton University, Princeton, New Jersey 08544, USA Princeton Center for Theoretical Science, Princeton University, Princeton, New Jersey 08544, USA a...

Laser-induced topological transitions in phosphorene with inversion symmetry