Evolution of Nagaoka phase with kinetic energy frustrating hopping

Abstract

We investigate, using the density-matrix renormalization group, the evolution of the Nagaoka state with t′ hopping that frustrates the hole kinetic energy in the U=∞ Hubbard model on the square and anisotropic triangular lattices. We find that the Nagaoka ferromagnet survives up to a rather small t'c/t∼0.2. At this critical value, there is a transition to an antiferromagnetic phase that depends on the lattice: a Q=(Q,0) spiral order, which continuously evolves with t′, for the triangular lattice and the usual Q=(π,π) Néel order for the square lattice. Remarkably, the local magnetization takes its classical value for all considered t′ (t′/t≤1). Our results show that the recently found classical kinetic antiferromagnetism, a perfect counterpart of Nagaoka ferromagnetism, is a generic phenomenon in these kinetically frustrated electronic systems.