Resonance scattering and singularities of the scattering function

Abstract

Recent studies of transport phenomena with complex potentials are explained by generic square root singularities of spectrum and eigenfunctions of non-Hermitian Hamiltonians. Using a two channel problem we demonstrate that such singularities produce a significant effect upon the pole behaviour of the scattering matrix, and more significantly upon the associated residues. This mechanism explains why by proper choice of the system parameters the resonance cross section is increased drastically in one channel and suppressed in the other channel.

4 pages, 3 figures

References in corpus (3)

• Coulomb analogy for nonhermitian degeneracies near quantum phase transitions
• Exceptional points in the spectra of atoms in external fields
• A return to observability near exceptional points in a schematic PT-symmetric model

Cited by in corpus (1)

• Spectral Singularities and Zero Energy Bound States