Spectral and transport properties of the PT-symmetric dimer model

Compatibility of transport effects in non-Hermitian nonreciprocal systems

“…Here, we address these connections for the general, nonreciprocal and non-Hermitian case. Aiming at a de-scription that is physical and flexible, we adopt the unifying perspective of transport, which has been instrumental to identify the specific signatures of individual physical effects in Hermitian [46,47] and non-Hermitian settings [44,45,[48][49][50][51][52][53][54][55][56][57][58][59][60][61][62]. This perspective allows us to analytically formulate the spectral conditions for a range of distinct physical phenomena, such as reflectionless scattering [49,52], transparency [56], coherent perfect absorption [44,45,50], and lasing [50,51,63,64], and contrast these with the quantisation conditions of finite systems with open or periodic boundary conditions.…”

PT–symmetric tight-binding model with asymmetric couplings

“…The case of symmetric couplings, when ν n,n+1 = ν n,n−1 = const, has been analyzed widely in Ref. [11]. Below we consider an asymmetric coupling which is characterized by two alternating and non-equal values of ν.…”

“…The case of symmetric couplings, when ν n,n+1 = ν n,n−1 = const, has been analyzed widely in Ref. [11].…”

PT-symmetric transport in non-PT-symmetric bi-layer optical arrays

“…where " * " stands for the complex conjugation. This symmetry can be compared with that emerging for various PT -symmetric Hamiltonians [7,[19][20][21]. Clearly, it differs from the standard one, M 22 = M * 11 , M 21 = M * 12 , that originates from time-reversal symmetry.…”