Interplay between Mutual Capacitive Coupling and Tunneling in Silicon Single Electron Transistor Coupled to Dopant Atom

Abstract

We have studied mutual capacitive coupling and tunneling in the silicon single  electron transistor coupled to a dopant atom. We observed a spectacular  enhancement of the conductance through the single electron transistor when  transport occurs by resonant tunneling via the dopanant atom. We found that in  certain range of temperature the mesocopic fluctuations of coulomb blockade peaks  are suppressed. The coulomb blockade have equal height which is determined by  the transparencies of the single electron transistor tuned barriers and it is  independent of the electron motion inside the single electron transistor island. The  peak height remains constant over a large number of coulomb blockade oscillations  and varies weakly with the gate voltage due to the way the gate couples to the single  electron transistor tunnel barriers. A strong modulation of the peak height on a scale  of several coulomb balckade osciallations was considered. In silicon nanostructures  based on doping modulation charge traps occur naturally at the borders of the  doped regions, where the dopants are likely to diffuse away from their majority  distribution and from nearly isolated charge traps. We have studied the effects  associated with a single charge trap in the coulomb blocade oscillations of single  electron trap. Our results are used to assess the feasibility of using single electron  transistor as a means to manipulate and readout single dopant atoms in silicon. We  found that at low temperatures the linear conductance can be derived from a circuit  approach in which the donar single electron transistor system is replaced by a circuit  of resistors. Capative and tunneling coupling were found resulting an increase of the  conductance through the single electron transistor by up to one order of magnitude.  The obtained results were compared with previous obtained results and were found  in good agreement.