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Spin Selectivity in Electron Transmission Through Self-Assembled Monolayers of Double-Stranded DNA

2011; American Association for the Advancement of Science; Volume: 331; Issue: 6019 Linguagem: Inglês

10.1126/science.1199339

1095-9203

Benjamin Göhler, V. Hamelbeck, Tal Z. Markus, Matthias Kettner, G F Hanne, Z. Vager, Ron Naaman, H. Zacharias,

Quantum and electron transport phenomena

In electron-transfer processes, spin effects normally are seen either in magnetic materials or in systems containing heavy atoms that facilitate spin-orbit coupling. We report spin-selective transmission of electrons through self-assembled monolayers of double-stranded DNA on gold. By directly measuring the spin of the transmitted electrons with a Mott polarimeter, we found spin polarizations exceeding 60% at room temperature. The spin-polarized photoelectrons were observed even when the photoelectrons were generated with unpolarized light. The observed spin selectivity at room temperature was extremely high as compared with other known spin filters. The spin filtration efficiency depended on the length of the DNA in the monolayer and its organization.