Chiral-induced angular momentum radiation in single molecular junctions

Abstract

We study angular momentum radiation from electrically-biased chiral single molecular junctions using the nonequilibrium Green's function method. Using single helical chains as examples, we make connections between the ability of a chiral molecule to emit photons with angular momentum to the geometrical factors of the molecule. We point out that the mechanism studied here does not involve the magnetic moment. Rather, it relies on inelastic transitions between scattering states originated from two electrodes with different chiral properties and chemical potentials. The required time-reversal symmetry breaking is provided by nonequilibrium electron transport. Our work sheds light on the relationship between geometrical and optoelectrical chiral properties at single molecular limit.