  We propose a superconducting circuit that shows a super-radiant phase
transition (SRPT) in the thermal equilibrium. The existence of the SRPT is
confirmed analytically in the limit of an infinite number of artificial atoms.
We also perform numerical diagonalization of the Hamiltonian with a finite
number of atoms and observe an asymptotic behavior approaching the infinite
limit as the number of atoms increases. The SRPT can also be interpreted
intuitively in a classical analysis.
