24.03.25 - Carmen Herrmann "First-principles approaches to chiral induced spin selectivity"

First-principles approaches to chiral induced spin selectivity

Molecular conductance is measured in different experimental setups such as scanning tunneling microscopes, molecular break junctions, and nanoparticle arrays. The motivation behind these experiments is not only studying potential reproducible nanoscale building blocks for electronics or spintronics but also learning about molecules under unusual conditions. Using the spin degree of freedom in such settings offers fascinating options for nanoscale functionality, and also provides new experimental data for improving our insight into fundamental aspects of nonequilibrium physics at that scale. Chiral induced spin selectivity (CISS) is a particularly intriguing example of this, as it leads to spin preferences in transported electrons, even though the molecules themselves are diamagnetic. This is not only fundamentally interesting but also potentially relevant for areas such as efficient spin injection in spintronic devices, electrocatalysis and hydrogen production, enantiomer separation, efficient electron transfer in biological systems, and the homochirality of living systems. The mechanism underlying CISS is not yet understood. We discuss recent progress in the first-principles description of CISS, along with an overview of recent developments in theory and experiment.