Conductance Oscillations in Asymmetric Quantum Dot Structures

The electrical transfer characteristics of asymmetric quantum dot structures are studied using a master equation model. The patterns of oscillations caused by Coulomb blockade and charge trapping at the quantum dots are investigated in relation to the capacitors coupling the dots to the gate electrode. The model is used to study double and triple quantum dot structures and the dynamics of charge transfer are discussed. It is shown that the capacitor mismatch results in different transconductance patterns, and the period of oscillations is found to depend on the smallest dot-gate coupling capacitance and the relative values of capacitances.