Fig. 6: Confirmation of 3D generalized Brillouin zone by spectra, ameba, and Ronkin function.
From: Experimental probe of point gap topology from non-Hermitian Fermi-arcs
a Schematics of the geometry of the tight-binding model identical to the experimental sample shown in Fig. 3a. b The gray area represents the 3D periodic boundary condition spectra \({\sigma }^{P}\). The discrete dots are the calculated eigenfrequencies from diagonalizing of the real-space Hamiltonian shown in (a) with an imaginary on-site random potential distributed uniformly in \([-w,w]\) added at each boundary site. The orange, blue, and green markers correspond to \(w=0\), \(w=0.2\), and \(w=0.3\), respectively. c, e Ronkin functions \({R}_{f}\left({{\boldsymbol{\mu }}}\right)\) on different slices of the 3D parameter space (\({\mu }_{x},{\mu }_{y},{\mu }_{z}\)) taken at \({E}_{1}\notin \,{\sigma }^{U}\) (c) and \({E}_{2}\in \,{\sigma }^{U}\) (e) labeled in (b). The solid lines (dashed lines) are the outer (inner) boundaries of the corresponding amebas \({A}_{f}\), and the blue single dot in (e) denotes \({{{\boldsymbol{\mu }}}}_{\min }({E}_{2})\). d, f The 3D ameba taken at \({E}_{1}\) and \({E}_{2}\).
