Objective:

• Establish control & design parameters for charge qubits
• Determine the range of feasible surface and barrier gate voltages
• Investigate effects of excited states

Approach:

• Surface and Barrier gates modeled by TCAD potentials
  
• Coupled impurity potential gives rise to molecular states
• Surface gates create left/right localized states

Results / Impact:

Smooth voltage control is shown for most configurations
At higher voltages, the excited states mingle with the lowest states, limiting the range of operating voltages.
Simulation tool for charge qubit experiments & data analysis.