Large Magnetoresistance Ratio in Ferromagnetic Single-Electron Transistors in the Strong Tunneling Regime

摘要

We study transport through a ferromagnetic single-electron transistor. Theresistance is represented as a path integral, so that systems where the tunnelresistances are smaller than the quantum resistance can be investigated. Beyondthe low order sequential tunneling and co-tunneling regimes, a largemagnetoresistance ratio at sufficiently low temperatures is found. In theopposite limit, when the thermal energy is larger than the charging energy, themagnetoresistance ratio is only slightly enhanced.