Josephson energy: E_J cos φ̂ with I_c = 2πE_J/Φ_0; Φ_0 = h/(2e) flux quantum

Josephson 1962 dc relations: the potential energy of a Josephson junction as a function of the gauge-invariant phase difference φ across the tunnel barrier is U(φ) = −E_J cos φ, where E_J is the Josephson coupling energy (of order μeV–meV…