Fig. 7: Spectral function A(E,k) identifying point gaps in the complex frequency plane.
From: Experimental probe of point gap topology from non-Hermitian Fermi-arcs
The 1D periodic boundary condition spectrum with the model Hamiltonian \(H\left(k\right)=-i+{e}^{{ik}}+t{e}^{-{ik}}\) for \(t = 1.0\) and \(t = 1.2\), respectively in (a, b). c, d The corresponding spectral function \(A\left(E={E}_{B},{{\boldsymbol{k}}}\right)\) as a function of \(k\) for the Hamiltonicans in (a, b), respectively. The filled stars, open circles, and open triangles denote the position of \({E}_{B}\), \({k}_{1}\), and \({k}_{2}\). e The \(y\)-open boundary condition band structure for the Hamiltonian defined in Eq. 1 with \({k}_{z}=0.5\pi\). f The corresponding spectral function \(A\left(E,{{\boldsymbol{k}}}\right)\) in the \(E-{k}_{x}\) plane. g The spectral function \(A\left(E={E}_{S},{{\boldsymbol{k}}}\right)\) at the white dashed line as a function of \({k}_{x}\). The red and cyan dashed lines (circle and triangle) highlight the position of \({k}_{x1}\) and \({k}_{x2}\).
