Artifacts that mimic ballistic magnetoresistance
نویسندگان
چکیده
We have investigated the circumstances underlying recent reports of very large values of ballistic magnetoresistance (BMR) in nanocontacts between magnetic wires. We find that the geometries used are subject to artifacts due to motion of the wires that distort the nanocontact thereby changing its electrical resistance. Since these nanocontacts are often of atomic scale, reliable experiments would require stability on the atomic scale. No method for achieving such stability in macroscopic wires is apparent. We conclude that macroscopic magnetic wires cannot be used to establish the validity of the BMR effect. r 2004 Elsevier B.V. All rights reserved.
منابع مشابه
Quantum Interference Control of Ballistic Magneto- resistance in a Magnetic Nanowire Containing Two Atomic- Size Domain Walls
The magnetoresistance of a one-dimensional electron gas in a metallic ferromagnetic nanowire containing two atomic-size domain walls has been investigated in the presence of spin-orbit interaction. The magnetoresistance is calculated in the ballistic regime, within the Landauer-Büttiker formalism. It has been demonstrated that the conductance of a magnetic nanowire with double domain walls...
متن کاملBallistic anisotropic magnetoresistance.
Electronic transport in ferromagnetic ballistic conductors is predicted to exhibit ballistic anisotropic magnetoresistance-a change in the ballistic conductance with the direction of magnetization. This phenomenon originates from the effect of the spin-orbit interaction on the electronic band structure which leads to a change in the number of bands crossing the Fermi energy when the magnetizati...
متن کاملBallistic magnetoresistance in a nanocontact between a Ni cluster and a magnetic thin film
We present measurements of ballistic magnetoresistance in nanocontacts grown by electrodeposition of Ni microclusters on magnetic thin films covered by aluminum oxide layers, using a technique proposed by Schad et al. @D. Allen, R. Schad, G. Zangari, I. Zana, D. Yang, M. C. Tondra, and D. Wang, J. Vac. Sci. Technol. A. 18, 1830 ~2000!; Appl. Phys. Lett. 76, 407 ~2000!; D. Allen, R. Schad, G. Za...
متن کاملBallistic magnetoresistance in small-size carbon nanotubes devices
We theoretically study the magnetoresistance of single wall carbon nanotubes (SWCNTs) in the ballistic transport regime, using a standard tight-binding approach. The main attention is directed to spin-polarized electrical transport in the presence of either axial or perpendicular magnetic field. The method takes into account both Zeeman splitting as well as size and chirality effects. These fac...
متن کاملInteraction-induced magnetoresistance: from the diffusive to the ballistic regime.
We study interaction-induced quantum correction deltasigma(alphabeta) to the conductivity tensor of electrons in two dimensions for arbitrary Ttau, where T is the temperature and tau the transport mean free time. A general formula is derived, expressing deltasigma(alphabeta) in terms of classical propagators ("ballistic diffusons"). The formalism is used to calculate the interaction contributio...
متن کامل