Spin gating of mesoscopic devices

We review the possibility to achieve “spin-gating” of mesoscopic devices, i.e. the possibility of an external spin control of the electronic properties of nanodevices. Rather than the Coulomb interaction, which is responsible for electric-charge gating, we consider two other mechanisms for spin gating. These are on the one hand the magnetic exchange interaction in magnetic devices and on the other hand the spin-orbit coupling (“Rashba effect”), which is prominent in low dimensional conductors. A number of different phenomena demonstrating the spin gating phenomenon is discussed, including (a) the spintro-mechanics of magnetic shuttling in a tunneling device comprising a movable non-magnetic quantum dot coupled by electronic tunneling and by magnetic exchange interactions to ferromagnetic leads, (b) Rashba spin splitting at a break-junction supported nanowire attached by tunnel contacts to two biased electrodes ([L] and [R]), and (c) the spin-gated weak superconductivity of a normal-metal nanowire (NW) in contact with a ferromagnetic insulator (FI) that bridges the gap between two superconductors (S) while a magnetic STM tip, acting as a spin gate, can be used to inuence the magnetization in parts of the nanowire. 82