Resonant tunneling in coupled quantum dots

We have applied a scaled version of the Kohn-Sham equations of density-functional theory to study the charge distribution at the condition of resonant tunneling in coupled quantum dots. We find that the tunneling process is governed by the symmetry properties of the resonantly coupled quantum-dot states. At resonance, the coupled atomiclike quantum-dot states form bonding and antibonding molecular resonant-tunneling states. The charge distribution of the bonding-type state is given. In addition, we find asymmetries of the charge in the barrier vs voltage (analogous to I-V curves) as a result of electron-electron interactions between electrons in the excited tunneling and ground states.