Physics – Condensed Matter – Mesoscale and Nanoscale Physics
Scientific paper
2011-06-21
Phys. Rev. B 84, 125439 (2011)
Physics
Condensed Matter
Mesoscale and Nanoscale Physics
11 pages, 4 figures. Submitted
Scientific paper
10.1103/PhysRevB.84.125439
We theoretically investigate spin-polarized transport in a system composed of a ferromagnetic Scanning Tunneling Microscope (STM) tip coupled to an adsorbed atom (adatom) on a host surface. Electrons can tunnel directly from the tip to the surface or via the adatom. Since the tip is ferromagnetic and the host surface (metal or semiconductor) is non-magnetic we obtain a spin-diode effect when the adatom is in the regime of single occupancy. This effect leads to an unpolarized current for direct bias (V > 0) and polarized current for reverse (V < 0) bias voltages, if the tip is nearby the adatom. Within the nonequilibrium Keldysh technique we analyze the interplay between the lateral displacement of the tip and the intra adatom Coulomb interaction on the spindiode effect. As the tip moves away from the adatom the spin-diode effect vanishes and the currents become polarized for both V > 0 and V < 0. We also find an imbalance between the up and down spin populations in the adatom, which can be tuned by the tip position and the bias. Finally, due to the presence of the adsorbate on the surface, we observe spin-resolved Friedel oscillations in the current, which reflects the oscillations in the calculated LDOS of the subsystem surface+adatom.
Egues Carlos J.
Penteado P. H.
Seridonio Antonio C.
Souza Fabricio M.
Vernek Edson
No associations
LandOfFree
Scanning Tunneling Microscope Operating as a Spin-diode does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with Scanning Tunneling Microscope Operating as a Spin-diode, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Scanning Tunneling Microscope Operating as a Spin-diode will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-204889