The lowest conductance step for a Ni nanocontact is anomalously small in comparison with the large expected number of conducting channels. We present electronic structure calculations for an extremely idealized Ni nanobridge consisting of just a monatomic nanowire. Our calculations show that no less than eight single spin bands cross the Fermi level in a nonmagnetic Ni monatomic wire, dropping marginally to seven in the more stable, fully ferromagnetic state. However, when we build in the wire a magnetization reversal, or domain wall, by forcing the net magnetization to be zero, we suddenly find that d-electrons selectively cease to propagate across the wall. s-electron propagation remains, and can account for the small observed conductance steps. (C) 2002 Elsevier Science B.V. All rights reserved.
|Titolo:||Selective d-state conduction blocking in nickel nanocontacts|
|Autori:||Smogunov A; DAL CORSO A; Tosatti E|
|Data di pubblicazione:||2002|
|Digital Object Identifier (DOI):||10.1016/S0039-6028(02)01323-7|
|Appare nelle tipologie:||1.1 Journal article|