Speaker
Description
The chirality-induced spin selectivity (CISS) effect, wherein chiral molecular structures preferentially transmit electrons of a specific spin orientation, has been increasingly attributed to the presence of spin–orbit coupling (SOC) in the system. Recent theoretical developments suggest that, in strongly chiral environments, SOC may acquire a geometric component arising from the molecular structure itself. In this context, we have performed Surface Enhanced Raman Spectroscopy (SERS) measurements on enantiomeric pharmaceutical compounds and observed distinct variations in spectral shape and intensity between left- and right-handed forms. These asymmetries are hypothesized to originate from CISS-related spin filtering effects. To elucidate the role of molecular chirality and geometry in generating these differences, we propose a theoretical study based on a simplified model of a spin-½ particle propagating along a helical trajectory under the influence of geometric SOC. Through this model, we aim to demonstrate that key physical properties—specifically, the energy spectrum and density of states (DOS)—are explicitly dependent on the helical geometry. This approach provides a framework for interpreting the experimental SERS results and contributes to a deeper understanding of the fundamental mechanisms underlying CISS.