Role of Exchange Interactions in the Magnetic Response and Intermolecular Recognition of Chiral Molecules

Abstract

The physical origin of so called Chirality-Induced Spin Selectivity (CISS) effect has puzzled experimental and theoretical researchers over the past few years. Early experiments were interpreted in terms of unconventional spin-orbit interactions mediated by the helical geometry. However, more recent experimental studies have clearly revealed that electronic exchange interactions also play a key role in the magnetic response of chiral molecules in singlet states. In this investigation, we use spin polarized closed-shell Density-Functional Theory calculations to address the influence of exchange contributions to the interaction between helical molecules as well as of helical molecules with magnetized substrates. We show that exchange effects result in differences in the interaction properties with magnetized surfaces, shedding light into the possible origin of two recent important experimental results: enantiomer separation and Magnetic Exchange Force Microscopy with AFM tips functionalized with helical peptides.

Unconventional Meissner screening induced by chiral molecules in a conventional superconductor

“…Shift in the average local magnetic field Bloc between the superconducting and normal state in a ChMs/Nb (65 nm) sample as a function of muon implantation energy E (bottom axis) and average muon stopping depth z (top axis) for B ext = +300 Gauss (light blue symbols) and B ext = −300 Gauss (green symbols). The shift in Bloc is determined as the difference between Bloc at T = 2.8 K and Bloc at T = 10 K normalized to Bloc at T = 10 K. interaction between ChMs [31]. The dependence of the unconventional Meissner screening effect on the relative orientation of the net polarization of the ChMs about B ext also supports our theoretical model, which assumes a spin activity of the ChMs layer, as discussed below.…”

Chirality-driven topological electronic structure of DNA-like materials

“…It has been argued 6 , 30 – 32 that the exchange interaction between the molecule and the substrate induces the selective adsorbance by considering a transient chirality-dependent spin polarization in the molecules. However, Refs.…”

Recent developments in the chiroptical properties of chiral plasmonic gold nanostructures: bioanalytical applications

“…The ORD is related to the real part of chirality parameter. It is expressed as the unequal rotation for plane polarized light of different wavelengths [53]. Optical activity is the ability of a molecule to rotate the plane polarized light [54].…”