Non-Hermitian transparency and one-way transport in low-dimensional lattices by an imaginary gauge field

摘要: Unidirectional and robust transport is generally observed at the edge of two- or three-dimensional quantum Hall topological insulator systems. A hallmark these systems protection, i.e., existence propagative states that cannot be scattered by imperfections disorder in system. different less explored form arises non-Hermitian presence an imaginary gauge field. As compared to topologically protected systems, can lower dimensional (i.e., one dimensional) In this work properties one-dimensional tight-binding lattices with field are theoretically investigated, physical mechanism underlying one-way highlighted. Back scattering here forbidden because reflected waves evanescent rather than propagative. Remarkably, spectral transmission lattice shown mapped onto corresponding Hermitian lattice, without field, but computed complex plane. particular, large values transmittance becomes equal 1, even imperfections. This phenomenon referred as transparency. Robust also realized a more realistic setting, namely heterostructure which disordered embedded between two homogeneous lattices. Such double realizes asymmetric (nonreciprocal) wave transmission. implementation transparency, based on light chain optical microring resonators, suggested.