Figure 4

Effective circuit diagram of three charge qubits (green) couple through grounded SQUIDs (blue) with Josephson energy \(E_{J_{s}}\) and effective capacitor \(C_{s}/2\). Moreover \(C_{c}\) is the coupling capacitance, and \(\Phi _{1}\), \(\Phi _{2}\), \(\Phi _{3}\), \(\Phi _{s_{1}}\) and \(\Phi _{s_{2}}\) are node fluxes that define the degrees of freedom of the qubits and SQUIDs