SU(2)xU(1) gauge theory for magnetic and pairing fluctuations in the 2D Hubbard model

We analyze the interplay of antiferromagnetism and pairing fluctuations in the two dimensional Hubbard model with a moderate repulsive interaction. In particular, we present a gauge theory description for fluctuations where the stiffnesses are computed in the coexisting phase from renormalization mean-field equations via the functional renormalization group (fRG). We show a sizable doping regime with robust pairing coexisting with Néel or incommensurate antiferromagnetism. The fluctuations suppress any magnetic order at finite temperature while the Kosterlitz-Thouless critical temperature for pairing remains finite.