>>48
Under the limit with the large self-inductance, two first terms in the Hamiltonian form a double-well potential near φ = φ0 / 2 .
The charge Q is a canonically conjugated variable to the phase difference across the junction Ψ = 2πφ / φ0 （→ ( 5 )）.
The Hamiltonian ( 10 ) can be reduced to that of a two-state system. All elementary operations can be performed by controlling the applied magnetic field.
