Topologically enforced bifurcations in superconducting circuits

The authors gratefully acknowledge financial support from the DFG Grants No. BR 1528/7, No. BR 1528/8, No. BR 1528/9, No. SFB 910, and No. GRK 1558, as well as inspiring discussion with Jordi Pico, Jan Totz, and Anna Zakharova. This work was supported by the Spanish Ministry through Grant No. MAT2014-58241-P and the FPI program.