Topology of multipartite non-Hermitian one-dimensional systems

The multipartite non-Hermitian Su-Schrieffer-Heeger model is explored as a prototypical example of one-dimensional systems with several sublattice sites for unveiling intriguing insulating and metallic phases no Hermitian counterparts. These are characterized by composite cyclic loops multiple complex-energy bands encircling single or exceptional points (EPs) on the parametric space real imaginary energy. We show topology these similar to well-known topological objects like M\"obius strips Penrose triangles, can be quantified nonadiabatic geometric phase which includes contributions only from participating bands. analytically derive complete diagram boundaries model. further examine connection between EPs associated topology.