Gauge theory for the cuprates near optimal doping

Recent experiments have revealed remarkable new features of the optimal doping state of cuprate superconductors, namely, a peak in the specific heat for the hole-doped case and a state with Fermi pockets but only fluctuating antiferromagnetic order for the electron-doped case. The authors propose a unified SU(2) gauge theory with a Higgs field and demonstrate how it can explain these disparate phenomena by way of topological phase transitions and crossovers.