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Accueil > Groupes scientifiques > Groupe Electrons Photons Surfaces > Dynamique d’électrons et de spin

Chiral surfaces

par Rowe Alistair - publié le , mis à jour le

The intimate relationship between chirality and electron spin magnetism is an emerging field based on the action of chiral objects (molecules, surfaces states) as a spin filter for electron transport. By analogy with differential absorption of polarized light by chiral molecules, spin polarized electrons which are de facto chiral objects, can interact with chiral molecules by setting off a spin dependent scattering asymmetry.

Contact : Yves Lassailly

In collaboration with University of Manchester (N. Lewis and E. Seddon) and University of Nebraska (T.J. Gay group), we investigate the spin polarization on semi-conductor and metal surfaces due both the Rashba effect and the lack of inversion symmetry of the surface lattice. Band structure calculations on chiral surfaces predict that eigenstates at specific k directions have components of the spin polarization vector P which are strongly dependent on the chirality of the surface. Using the spin-resolved UV photoemission equipment on APE synchrotron beamline in Elettra, we have shown that a weak localized surface state of the Si(110)-16x2 reconstructed chiral surfaces has a small non-zero longitudinal spin polarization (Px of 5%) unlike achiral surfaces.

[en]Si(110) 16x2 single domain chiral surface : Px component of the spin polarization measurement versus the binding energy of the surface state localized between 0.7-0.9 eV. The polarization presents a mirror symmetry for the two enantiometric surfaces.