Single-electron computing without dissipation

The possibility of performing single-electron computing without dissipation in an array of tunnel-coupled quantum dots is studied theoretically, taking the spin gate NOT (inverter) as an example. It is shown that the logical operation can be implemented at the stage of unitary evolution of the electron subsystem, although complete switching of the inverter cannot be achieved in a reasonable time at realistic values of model parameters. The optimal input magnetic field is found as a function of the interdot tunneling energy and intradot Coulomb repulsion energy. (C) 1997 American Institute of Physics.