Controlling spin transport at the atomic scale by orbital engineering

Oren Tal, Chemical Physics, Weizmann Institute, Rehovot, Israel
Ran Vardimon, Chemical Physics, Weizmann Institute, Rehovot, Israel
Marina Klionsky, Chemical Physics, Weizmann Institute, Rehovot, Israel

Electronic spin transport across atomic-scale junctions is very sensitive to the fine details of the electronic structure at the junction constriction. We use this sensitivity to control and explore atomic-scale spin transport. By modifying the electronic structure of atomic contacts with the aid of local chemical manipulations, we fabricated atomic scale junctions with up to 100% spin-polarized conductance as verified by shot noise measurements. Interestingly, the spin filtering is done at the length scale of an atom, leading to a single spin-polarized transmission channel with significant conductance of ~0.6 (e^2)/h. The high spin-polarization is preserved for further elongation of the atomic-scale conductor. The presented orbital engineering approach can open the door for fundamental study of atomic-scale spin transport with attractive implications for spintronics.