5 papers
Exponentially growing bulk Green functions as signature of nontrivial non-Hermitian winding number in one dimension
Heinrich-Gregor Zirnstein, Bernd Rosenow
A nonzero non-Hermitian winding number indicates that a gapped system is in a nontrivial topological class due to the non-Hermiticity of its Hamiltonian. While for Hermitian system…
Topological Magnetoelectric Effect: Nonlinear Time-Reversal-Symmetric Response, Witten Effect, and Half-Integer Quantum Hall Effect
Heinrich-Gregor Zirnstein, Bernd Rosenow
Topological insulators (TIs) in three space dimensions can be characterized by a quantized magnetoelectric coefficient. However, this coupling does not have experimentally observab…
Bulk-boundary correspondence for non-Hermitian Hamiltonians via Green functions
Heinrich-Gregor Zirnstein, Gil Refael, Bernd Rosenow
Genuinely non-Hermitian topological phases can be realized in open systems with sufficiently strong gain and loss; in such phases, the Hamiltonian cannot be deformed into a gapped…
Evolution of the transmission phase through a Coulomb-blockaded Majorana wire
Casper Drukier, Heinrich-Gregor Zirnstein, Bernd Rosenow +2
We present a study of the transmission of electrons through a semiconductor quantum wire with strong spin-orbit coupling in proximity to an s-wave superconductor, which is Coulomb-…
Time-reversal-symmetric topological magnetoelectric effect in three-dimensional topological insulators
Heinrich-Gregor Zirnstein, Bernd Rosenow
One of the hallmarks of time-reversal-symmetric topological insulators in three dimensions is the topological magnetoelectric effect (TME). So far, a time-reversal breaking variant…