80 citations · 480 across the 35 of their papers we have counts for
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Gaplessness of Landau Hamiltonians on hyperbolic half-planes via coarse geometry
Matthias Ludewig, Guo Chuan Thiang
We use coarse index methods to prove that the Landau Hamiltonian on the hyperbolic half-plane, and even on much more general imperfect half-spaces, has no spectral gaps. Thus the e…
The Fermi gerbe of Weyl semimetals
Alan Carey, Guo Chuan Thiang
In the gap topology, the unbounded self-adjoint Fredholm operators on a Hilbert space have third homotopy group the integers. We realise the generator explicitly, using a family of…
On spectral flow and Fermi arcs
Guo Chuan Thiang
We introduce spectral flow techniques to explain why the Fermi arcs of Weyl semimetals are topologically protected against boundary condition changes and perturbations. We first an…
Cobordism invariance of topological edge-following states
Matthias Ludewig, Guo Chuan Thiang
We prove that a spectral gap-filling phenomenon occurs whenever a Hamiltonian operator encounters a coarse index obstruction upon compression to a domain with boundary. Furthermore…