Emerging Anomalous In-Gap Modes In Non Hermitian System

Non-Hermitian systems have emerged recently due to their unique properties, like faster propagation of wave packets in contrast to Hermitian counterparts, non-reciprocal wave guiding, etc. In general, non-reciprocity can be tailored through unequal directional hopping between two different sites and also via onsite gain/loss balancing. The goal of this research is to examine the impact of both non-Hermitian constitutive parameters, i.e directionality and gain/loss, in a coupled one-dimensional (1D) double-chain network. The directional hopping in a 1D system causes the localization of bulk modes at the boundaries, known as non-Hermitian skin effect (NHSE), whereas the precise tuning of the gain/loss parameters leads to a the emergence of zero energy in-gap modes.