Embedded Non-Hermitian Topology and Skin Effect

Non-Hermitian (NH) systems differ from their Hermitian counterparts and can exhibit a skin effect, a phenomenon in which an extensive number of eigenstates accumulate at an open boundary, which are dubbed `skin modes.' These skin modes are guaranteed by a non-vanishing winding number of the bulk point-gap on the complex energy plane. In this work, we consider NH models in D dimensions composed of coupled multi-layers of d-dimensional NH models (d