Metal-Mediated Tunable Spin-Selective Transport in Cholesterol-Based Metal–Organic Supramolecular Materials

Cholesterol serves as an ideal platform due to its intrinsic chirality and flexibility, which enable precise control over supramolecular properties. Recent studies have underscored the significance of supramolecular chirality in enhancing the spin filtering efficiency through the chiral-induced spin selectivity (CISS) effect, thus opening interesting avenues for advanced spintronic materials. In this study, we present cholesterol-based metal–organic supramolecular materials as promising candidates for CISS based spintronic applications. By employing metal-ion coordination, we demonstrate the capability to modulate the spin filtering efficiency by varying the type and concentration of metal ions. The key finding of this study is that both spin states of electrons can be effectively manipulated within a single system by varying chemical stimuli (achiral factors), such as the type and concentration of metal ions. This novel approach enables greater precision and ease in manipulating spin information in a CISS based supramolecular system. Furthermore, we successfully demonstrated the relationship between the circular dichroism (CD) and the degree of spin polarization with respect to different molar ratios of metal ions and ligands. Additionally, we investigated the contact potential difference (CPD) of the studied cholesterol-based polymers using magnetic field-dependent Kelvin probe force microscopy (KPFM), which further correlates with spin transport measurements. Notably, our findings represent the first instance of metal mediated spin-selective transport in a cholesterol-based system for achieving efficient spin filtering materials, signifying a crucial advancement in the field of spintronics.