Cotunneling mechanism of single-electron shuttling

The problem of electron transport by means of a dumbbell shaped shuttle in strong Coulomb blockade regime is solved. The electrons may be shuttled only in the cotunneling regime during the time spans when both shoulders of the shuttle approach the metallic banks. The conventional Anderson-like tunneling model is generalized for this case and the tunneling conductance is calculated in the adiabatic regime of slow motion of the shuttle. Non-adiabatic corrections are briefly discussed