Insights into the Mechanism underlying the Chiral-Induced Spin Selectivity: The effect of an Angle-Dependent Magnetic Field and Temperature

Chiral oligopeptide monolayers were adsorbed on a ferromagnetic surface and their magnetoresistance was measured as a function of the angle between the magnetization of the ferromagnet and the surface normal. These measurements were conducted as a function of temperature for both enantiomers. The angle dependence was found to follow the cosine square function. Quantum simulations revealed that the angular distribution could 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 only if it included electron-phonon interactions and dissipation.