Spin Filtering in DNA-like Materials
Chiral Induced Spin Selectivity is a unique phenomenon in which only electrons of one spin are able to pass through a chiral material. Due to this unique property, researchers are trying to better understand the effect in hopes of exploiting its benefits in sensing, storage, and quantum logic. One aspect of the CISS puzzle which is not yet fully understood is exploring how the radius of a chiral material affects its spin transmission and bands and why the Spin Selectivity effect occurs in the first place. To address these problems, numerical methods in MATLAB were applied to a DNA-like system consisting of a three atom unit cell. The computational results showed that as the radius of the system increased, spin transmission appeared to decrease. In addition, the bands grew flatter around the fermi level, indicating that the system could be approaching insulator-like properties. This means that there could be a specific radius that will maximize spin transmission. In addition, the radius was adjusted to match a real world system model of a Tellurium chain. The transmission found a magnetic field of .36 Teslas flowing through the model. Since this magnetic field is significant, it could help to indicate why spin filtering occurs. To conclude, the results provided help in explaining the CISS effect and the importance of geometrical properties like the radius but more research is still necessary to fully understand the phenomenon.