Molecular switches that exhibit bistable electron spins under ambient conditions have attracted growing interest due to their potential applications in quantum technologies, enabling exploitation of the chiral-induced spin selectivity (CISS) phenomenon on electron transfer processes. However, conferring chirality to 2D materials remains a major challenge in Materials Chemistry. Herein, we report the molecular engineering of a chiral spin-filtering 2D material -viz. 2D germanane (2D─GeH)-functionalized by covalent anchoring of chiral cysteine molecules via nucleophilic substitution. By interfacing the resulting chiral 2D material with a ferromagnetic electrode, we demonstrate the dynamic control of spin polarization by manipulating the external magnetic field, leading to two well-defined and electrically distinguishable quantum states. Additionally, the spin polarization direction can be tailored on-demand via enantiomeric configuration of the chiral ligand, promoting spin-dependent electron transport. These findings establish a platform for fine-tuning the spin polarization in chiral 2D materials, offering new opportunities for writing, erasing, and reading unconventional spin-selective molecular switches, and thereby paving the way for advances in quantum information processing and spintronics applications.
Lei et al. (Sun,) studied this question.