Trade-off between operational speed and error occurrence for single electron circuits on the quantum scale

We have investigated single-electron operation using the Landau-Zener (LZ) tunneling process with/without dissipation. LZ tunneling provides the trade -off between speed and the error of single electron operation in the two qu antum dots. We have applied the results of the LZ tunneling to the case of a single electron shift-register. For this device, the environment coupling suppresses the error rate at quite low temperatures.