  We propose a new qubit consisting of a superconducting ring with two ordinary
zero junctions and one ferromagnetic pi junction. In the system, two degenerate
stable states appear in the phase space without an external magnetic field
because of a competition between the zero and pi states. Quantum tunneling
between the two degenerate states leads to a formation of bonding and
antibonding states (coherent states) which are used as a bit. For manipulating
the states of the qubit, only small external magnetic field around zero is
required. This feature leads to a large-scale integration and a construction of
the qubit with a smaller size which is robust to the decoherence by external
noises.
