Orbital and Spin Magnetic Moments of Au (111) Surfaces with Adatoms and Chiral Molecules

Here, we perform theoretical calculations of spin and orbital magnetic moments on the metal surface of Au [111]. We use a supercell approach and density functional theory to study the gold surfaces in the slab configuration. We use a plane wave basis DFT package (VASP) in a 128-atom supercell and 20 Angstrom of vacuum. We hypothesize that a chiral molecule exhibits chiral polarizability and spin magnetic moment so that magnetic exchange interaction occurs between a chiral molecule and an adatom. To demonstrate this hypothesis we have calculated the exchange energy between an adatom and D-alanine/Cu(111) and L-alanine/Cu(111) on the surface. We also calculate the orbital magnetic moment of adatoms on a noble metal surface and its exchange interaction with the chiral molecule.