CrSbSe3 Nanowire: A Platform for Near-Perfect Spin Selectivity.

Spin-selective carrier transport in low-dimensional magnetic semiconductors is central to the development of next-generation spintronics. However, achieving robust spin-filtering together with long spin-coherence under nonequilibrium conditions remains a major challenge. Recently isolated by top-down exfoliation, the CrSbSe3 nanowire has emerged as a ferromagnetic semiconductor exhibiting enhanced coercivity compared to its bulk counterpart. Here, using first-principles density functional theory combined with quantum transport calculations, we demonstrate that the CrSbSe3 nanowire is a ferromagnetic semiconductor with a band gap of 1.26 eV. We identify superexchange interactions mediated by Se(p-orbitals) as the primary mechanism stabilizing its ferromagnetic order. Noncollinear spin calculations including spin-orbit coupling reveal an unchanged band topology near the Fermi level, suggesting long spin-coherence. Quantum transport calculations reveal robust spin-selective conduction, with the spin-injection factor approaching 100% for biases up to 0.6 V, independent of channel length, establishing the CrSbSe3 nanowire as a promising spin-filtering platform for spintronics.