Figure 1

(a) The experimental setup in which a circularly polarized laser is used to eject photoelectrons from a gold substrate coated with a structured monolayer consisting of either ssDNA or dsDNA oligomers. (b) The energetics involved in the photoemission process. Electrons are excited from below the Fermi level to above the vacuum level. The lowest unoccupied molecular orbital (LUMO) on the DNA is schematically presented. (c) Scheme of the organized layers of the (left) ssDNA and (right) dsDNA. Because of the rigid nature of the double strands, the monolayer is better organized.Reuse & Permissions

Figure 2

(a),(b) The energy distribution of the transmitted photoelectrons through a monolayer made from (a) ssDNA or (b) dsDNA oligomers. The electrons are ejected from the gold with a clockwise (cw, dotted line) or counterclockwise (ccw, solid line) circularly polarized laser. While in the first case, the electrons are spin polarized with the spin parallel to the electrons’ velocity, for ccw circular polarized laser, the spin is polarized antiparallel to the velocity. (c),(d) The magnetic moment as measured for the DNA-coated gold after subtracting the diamagnetic contribution of the gold. The magnetic moment measured for monolayer made from (c) single strands or (d) double strands measured at 300 (solid line with squares) and 30 K (solid line with circles). The dotted curves indicate the range of variation in the magnetic measurements obtained for different samples. The extreme values are shown: maximum as triangles and minimum as squares.Reuse & Permissions

Figure 3

Circular dichroism absorption spectra of ssDNA and dsDNA in buffer solution.Reuse & Permissions