Nonmagnetic single-molecule spin-filter based on quantum interference

Atindra Nath Pal (1, 2) , Dongzhe Li (3) , Soumyajit Sarkar (4) , Sudipto Chakrabarti (1) , Ayelet Vilan (1) , Leeor Kronik (4) , Alexander Smogunov (3) , Oren Tal (1)

1 Weizmann Institute of Science [Rehovot, Israël]
2 S. N. Bose National Centre for Basic Sciences
3 GMT - Groupe Modélisation et Théorie
4 Department of Materials and Interfaces [Rehovot, Israël]

Key spin transport phenomena, including magnetoresistance and spin transfer torque, cannot be activated without spin-polarized currents, in which one electron spin is dominant. At the nanoscale, the relevant length-scale for modern spintronics, spin current generation is rather limited due to unwanted contributions from poorly spin-polarized frontier states in ferro-magnetic electrodes, or too short length-scales for efficient spin splitting by spin-orbit interaction and magnetic fields. Here, we show that spin-polarized currents can be generated in silver-vanadocene-silver single molecule junctions without magnetic components or magnetic fields. In some cases, the measured spin currents approach the limit of ideal ballistic spin transport. Comparison between conductance and shot-noise measurements to detailed calculations reveals a mechanism based on spin-dependent quantum interference that yields very efficient spin filtering. Our findings pave the way for nanoscale spintronics based on quantum interference, with the advantages of low sensitivity to decoherence effects and the freedom to use non-magnetic materials.

Domaines: Physique [physics]; Science des matériaux [cond-mat.mtrl-sci]

Atindra Nath Pal, Dongzhe Li, Soumyajit Sarkar, Sudipto Chakrabarti, Ayelet Vilan, et al.. Nonmagnetic single-molecule spin-filter based on quantum interference. Nature Communications, 2019, 10, pp.5565. ⟨10.1038/s41467-019-13537-z⟩. ⟨cea-02402503⟩