A single electron transistor with quantum rings
  We Have developed the concept of a new kind of single-electron transistor in which the transport of the electron through a quantum wire is controlled by charged quantum rings. Using a 2D harmonic potential as the transverse constraint, we numerically investigated the transport of the electron through the wire. We have shown that in the low energy limit, for a suitable configuration of the rings, called the quadrupole configuration, we are able to adjust the conductance of the wire and therefore control the switching process. 
Ali Hosseinzadeh and Shahpoor Saeidian
cond-mat.mes-hall