arXiv:1709.09655 · Physical review. B./Physical review. B
Effects of interaction strength, doping, and frustration on the antiferromagnetic phase of the two-dimensional Hubbard model
Lorenzo Fratino, M. Charlebois, P. Sémon, G. Sordi, A.–M. S. Tremblay
Abstract
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 $\ensuremath{\delta}$, and temperature $T$. The N\'eel phase boundary is nonmonotonic as a function of $U$ and $\ensuremath{\delta}$. Frustration induced by second-neighbor hopping reduces N\'eel 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.