Spin filtering induced by quantum interference in organic antiferromagnetic junctions
Phys. Rev. B 114, 014419 – Published 16 July, 2026
DOI: https://doi.org/10.1103/b1hn-lvyy
Abstract
With the extended Su-Schrieffer-Heeger model and Green's function method, we theoretically demonstrate a significant spin-filtering effect in organic antiferromagnetic (AFM) junctions without any ferromagnetic elements or chiral structures. The spin filtering is caused by the large spin splitting of the destructive quantum interference (DQI) features, which results from the coexistence of the DQI and molecular AFM state. An analytical analysis based on Green's function indicates that the nondegenerate AFM wave functions of frontier orbitals is the source of the spin-resolved DQI. The electron-electron interaction is found crucial to achieve the AFM phase and thus the large spin polarization around the Fermi energy. The results are further confirmed by first-principles calculations. The robustness of the proposed mechanism under finite bias voltages and the generality of such effect in other organic AFM molecules are further examined. This work provides a new route to achieve large spin polarization in AFM junctions without ferromagnetic elements, and opens new avenues for organic AFM molecules as well as quantum interference effect in molecular spintronics.
