Filtering Spin and Orbital Moment in Centrosymmetric Systems

TL;DR

This paper demonstrates that orbital and spin moment filtering can be achieved in centrosymmetric systems by manipulating orbital couplings and symmetry conditions, challenging the common notion that inversion symmetry breaking is necessary.

Contribution

It introduces a novel mechanism for orbital and spin filtering in centrosymmetric systems through symmetry-controlled orbital couplings and atomic spin-orbit interaction.

Findings

Orbital moment filtering can occur without inversion symmetry breaking.

Symmetry conditions for orbital filtering depend on orbital coupling orientations.

Atomic spin-orbit interaction enables simultaneous spin and orbital filtering.

Abstract

The control of spin and orbital angular momentum without relying on magnetic materials is commonly accomplished by breaking of inversion symmetry, which enables charge-to-spin conversion and spin selectivity in electron transfer processes occurring in chiral media. In contrast to this perspective, we show that orbital moment filtering can be accomplished in centrosymmetric systems: the electron states can be selectively manipulated allowing for the preferential transfer of electrons with a particular orbital momentum orientation. We find that orbital moment filtering is indeed efficiently controlled through orbital couplings that break both mirror and rotational symmetries. We provide the symmetry conditions required for the electron transmission to achieve orbital filtering and relate them to the orientation of the orbital moment. The presence of atomic spin-orbit interaction in the centrosymmetric transmission medium leads to the selective filtering of spin and orbital moments. Our findings allow to identify optimal regimes for having highly efficient simultaneous spin and orbital moment filtering.