Controlling Spin Flow
through a Single Electron Transistor with the Kondo Effect
The figures show the differential conductance resulting from the Kondo
effect in a single electron transistor (SET). An unpaired electron
in the quantum dot inside the SET forms a weak chemical bond with electrons
in the leads. A magnetic field breaks this bond between 0 and 4T, splitting
the Kondo peak. At a higher field 14T one has a sharp threshold—for
electrons with low energy near Vds= 0 only one spin direction
can pass through the SET.
At higher energies, electrons with opposite spin can pass too. This effect may be useful in controlling electron spins for quantum computing.