Low-temperature conductance measurements have been performed upon a parallel quantum-dot configuration defined in the two-dimensional electron gas of a GaAs-As heterostructure. The observed Coulomb-blockade oscillations of the conducting dot exhibit pronounced periodic shifts as a consequence of the tunable coupling to the nonconducting dot. We show that the transport is essentially determined by the interdot capacitance and that the addition of a single electron to the nonconducting dot can switch the device conductance from a maximum to a Coulomb-blockade minimum.
- Received 30 December 1994
©1995 American Physical Society