Resonant Quantum Tunneling with Near-Hundred-Percent Spin Polarization in the Precisely Twisted Zinc-Complexed Chiral Molecular Moiré Superlattices

Abstract Programmed molecular assemblies have remarkably supported the growth of spintronics, molecular, and quantum devices. An important challenge in spintronics is to fabricate chiral nonmagnetic molecular assemblies as electron spin filter. We report the observation of chirality-induced spin selectivity in Zn-complexed molecular moiré superlattices of tryptophan. Importantly, the complexation reaction of d/l-tryptophan precursor moiré superlattices with Zn2+ ions resulted in new chiral superlattices with uniform periodicity based on precisely controlled twist angles. The presence of zinc at the twisted interfaces of the superlattices not only increased the tunneling current but also resulted in near-hundred-percent spin polarizability. The observed high spin polarizability and the increased conductivity were rationalized based on resonant quantum tunneling in the presence of both magnetic and electric fields that affected the electron transport through the chiral superlattices. Further, density-of-state calculations using the density functional theory also supported the increase in conductivity at the twisted interfaces.