Effects of interaction strength, doping, and frustration on the antiferromagnetic phase of the two-dimensional Hubbard model

Recent quantum-gas microscopy of ultracold atoms and scanning tunneling microscopy of the cuprates reveal new detailed information about doped Mott antiferromagnets, which can be compared with calculations. Using cellular dynamical mean-field theory, we map out the antiferromagnetic (AF) phase of the two-dimensional Hubbard model as a function of interaction strength U, hole doping δ, and temperature T. The Néel phase boundary is nonmonotonic as a function of U and δ. Frustration induced by second-neighbor hopping reduces Néel order more effectively at small U. The doped AF is stabilized at large U by kinetic energy and at small U by potential energy. The transition between the AF insulator and the doped metallic AF is continuous. At large U, we find in-gap states similar to those observed in scanning tunneling microscopy. We predict that, contrary to the Hubbard bands, these states are only slightly spin polarized.