Self-Consistent Calculation of the Charging Energy in a Quantum Dot Coupled to Leads

A self-consistent calculation scheme in the Coulomb-blockade regime is formulated to obtain the charging energy required in adding a single electron to a quantum dot which is electrostatically coupled to leads and a gate electrode. This method is applied to the quantum-dot transistor fabricated recently from a double-barrier heterostructure, showing that the electrostatic coupling to leads significantly influences the charging energy of the dot in such devices when the leads are close to the dot and the electron density is high in the leads.