Charge-2e skyrmion condensate in a hidden-order state

A higher-angular-momentum (l = 2) d density wave, a mixed triplet and a singlet, interestingly, admits skyrmionic textures. The skyrmions carry charge 2e and can condense into a spin-singlet s-wave superconducting state. In addition, a charge current can be induced by a time-dependent inhomogeneous spin texture, leading to quantized charge pumping. The quantum phase transition between this mixed triplet d density wave and the skyrmionic superconducting condensate likely leads to deconfined quantum critical points. We suggest connections of this exotic state to electronic materials that are strongly correlated, such as the heavy-fermion URu2Si2. At the very least, we provide a concrete example in which topological order and broken symmetry are intertwined, which can give rise to non-BCS superconductivity. DOI: 10.1103/PhysRevB.87.085114