Chiral Induced Spin Polarized Electron Current: Origin of the Chiral Induced Spin Selectivity Effect

The discovery of the chiral induced spin selectivity effect has provided a novel tool to study how active physical and chemical mechanisms may differ in chiral enantiomers; however, the origin of the effect itself is yet an open question. In this Letter, it is theoretically shown that two aspects must be fulfilled for the chiral induced spin selectivity effect to arise. First, chirality is a necessary condition for breaking the spin-degeneracy in molecular structures that do not comprise heavy elements. Second, dissipation is indispensable for the molecule to develop a nonvanishing spin-polarization. These theoretical conclusions are illustrated in terms of a few examples, showing the necessity of the two aspects to be coordinated for the emergence of the chiral induced spin selectivity effect.