Mathematics

Charge qubits are circuits consisting of a capacitance and a Josephson junction.Though macroscopic, they are phenomenologically described by a quantized Hamiltonian.By using the quasi-spin formulation of the BCS theory in the singular coupling limit, it is shown that the phenomenological Hamiltonian can be derived by means of a particular asymmetric realization of the theory of quantum fluctuations and of the quantum central limit theorem.