4 papers
Twisted (co)homology of non-orientable Weyl semimetals
Thijs Douwes, Marcus Stålhammar
The quasi-particle excitations in Weyl semimetals, known as Weyl fermions, are usually forced to emerge in charge-conjugate pairs by the Nielsen--Ninomiya theorem. When the Brillou…
Thermodynamics of analogue black holes in a non-Hermitian tight-binding model
D. F. Munoz-Arboleda, M. Stålhammar, C. Morais Smith
We present a non-Hermitian model with gain/loss and non-reciprocal next-nearest-neighbor hopping that emulates black-hole physics. The model describes a one-dimensional lattice wit…
The analytically tractable zoo of similarity-induced exceptional structures
Anton Montag, Jordan Isaacs, Marcus Stålhammar +1
Exceptional points (EPs) are non-Hermitian spectral degeneracies marking a simultaneous coalescence of eigenvalues and eigenvectors. Despite the fact that multiband -fold EPs (E…
Abelian Spectral Topology of Multifold Exceptional Points
Marcus Stålhammar, Lukas Rødland
The advent of non-Hermitian physics has enriched the plethora of topological phases to include phenomena without Hermitian counterparts. Despite being among the most well-studied u…