Gate-controlled Kondo effect in a single-molecule transistor with elliptical ferromagnetic leads

Abstract

We present low-temperature transport measurements of ${\mathrm{C}}_{60}$-based single-molecule transistors fabricated using ferromagnetic break junction devices with planar elliptical leads, revealing a gate-modulated single-channel spin-$\frac{1}{2}$ Kondo effect. The shape anisotropy and dipole interaction of the source and drain electrodes allows for the relative alignment of their respective magnetic moments to be switched between a parallel and an antiparallel configuration. Both the ferromagnetism of the electrodes and the manipulation of their magnetization are shown to impact the magnetotransport in the Kondo regime in a manner consistent with analytical results, but with a magnitude highly sensitive to the precise electrode-molecule geometry and associated coupling asymmetry.