Ground state phases of the triangular lattice Hubbard model from kinetic frustration*

The Hubbard model is a paradigmatic model of strongly correlated electrons that has been widely successful in the explanation of many emergent phenomena in solids. While a large body of work has been devoted to the square case, less is definitively established about the frustrated triangular model. The lack of particle-hole symmetry on a frustrated lattice results in a rich phase diagram, which can also be tested in various recently realized cold atom and solid-state Hubbard model emulators. Motivated by pioneering work of Haerter and Shastry [Phys. Rev. Lett. 95,087202 (2005)], we revisit the role of kinetically frustrated magnetism at finite hole density, a phenomenon by which magnetic order emerges without any underlying magnetic interactions. To do so, we study the infinite U model using the DMRG technique and find that the kinetically induced 120-degree antiferromagnetic state remains stable up to a hole density of approximately 0.2. At higher concentration of holes we report transitions to other phases including a renormalized metal, whose features we interpret analytically. We discuss the impact of our findings on the case of large but finite U, and investigate whether kinetic magnetism and superexchange collaborate or compete.