2000 character limit reached
Topological states in one-dimensional $\mathcal{P}\mathcal{T}$-symmetric systems (2503.20486v1)
Published 26 Mar 2025 in cond-mat.mes-hall and cond-mat.other
Abstract: We obtain a closed form expression for the energy spectrum of $\mathcal{P}\mathcal{T}$-symmetric superlattice systems with complex potentials of periodic sets of two $\delta$-potentials in the elementary cell. In the presence of periodic gain and loss we analyzed in detail a diatomic crystal model, varying either the scatterer distances or the potential heights. It is shown that at a certain critical value of the imaginary part of the complex amplitude, topological states depending on the lattice size and the configuration of the unit cell can disappear. This may happened at the $\mathcal{PT}$-symmetry breaking (exceptional) points.