Insights into the Mechanism of Chiral‐Induced Spin Selectivity: The Effect of Magnetic Field Direction and Temperature

Chiral oligopeptide monolayers are adsorbed on a ferromagnetic surface and their magnetoresistance is measured as a function of the angle between the magnetization of the ferromagnet and the surface normal. These measurements are conducted as a function of temperature for both enantiomers. The angle dependence is found to follow a changing trend with a period of 360°. Quantum simulations reveal that the angular distribution can be obtained only if the monolayer has significant effective spin orbit coupling (SOC), that includes contribution from the vibrations. The model shows that SOC only in the leads cannot reproduce the observed angular dependence. The simulation can reproduce the experiments if it included electron–phonon interactions and dissipation. Anisotropy magnetoresistance (AMR) and its temperature dependent are measured, in a crossbar geometry, for chiral oligopeptide monolayers. Periodicity of 360° is observed in the AMR. Quantum simulations reveal that the angular distribution can be simulated only if the monolayer has significant effective spin orbit coupling, which includes contribution from vibrations.