Phase diagram of the anisotropic triangular lattice Hubbard model

In our previous work [Phys. Rev. X 10, 021042 (2020)], we showed using density matrix renormalization group (DMRG) simulations on infinite cylinders that the triangular lattice Hubbard model with isotropic hopping hosts a chiral spin liquid phase at intermediate interaction strength. To better connect to experimental results in spin liquid candidate materials such as k-(BEDT-TTF)₂Cu₂(CN)₃, which are not precisely isotropic, in this work we add anisotropy to the model, making one of the three distinct bonds on the lattice stronger or weaker compared with the other two. We implement the anisotropy in two ways, one which respects the mirror symmetry of the cylinder and one which breaks this symmetry. Near the isotropic limit we find the three phases identified in our previous paper: an apparently metallic phase (which is possibly a Luther-Emery liquid), the chiral spin liquid, and a phase with spiral magnetic order. When one bond is weakened by a relatively small amount, the ground state quickly becomes the square lattice Néel order. When one bond is strengthened, we find a large variety of interesting phases, with the specific ones that appear depending on the orientation of the anisotropy and on the cylinder circumference.