2000/04/30 by Arne Brataas, X. H. Wang · 3 citations
Physics and Astronomy · #Magnetic properties of thin films #Quantum and electron transport phenomena #Surface and Thin Film Phenomena #cond-mat.mes-hall
paper · pdf · doi:10.1103/physrevb.64.104434
10 pages, 6 figures. accepted for publication in Phys. Rev. B
arxiv created 2001/06/28 · openalex publication_date 2001/08/23 · arxiv updated 2009/11/30 · openalex created_date 2016/06/24 · openalex updated_date 2026/07/28
The current through ferromagnetic single-electron transistors (SET's) is considered. Using path integrals the linear-response conductance is formulated as a function of the tunnel conductance versus quantum conductance and the temperature versus Coulomb charging energy. The magnetoresistance of ferromagnet--normal-metal--ferromagnet (F-N-F) SET's is almost independent of the Coulomb charging energy and is only reduced when the transport dwell time is longer than the spin-flip relaxation time. In all-ferromagnetic (F-F-F) SET's with negligible spin-flip relaxation time the magnetoresistance is calculated analytically at high temperatures and numerically at low temperatures. The F-F-F magnetoresistance is enhanced by higher-order tunneling processes at low temperatures in the ``off'' state when the induced charges vanish. In contrast, in the ``on'' state near resonance the magnetoresistance ratio is a nonmonotonic function of the inverse temperature.