Chia- Min Chung
Two-dimensional (2D) Hubbard model is one of the most fundamental model to describe cuprate superconductors. Despite the simple structure of the model, finding the ground state has been a great challenge due to the competing states. Several low-energy states have been found the candidate ground states with very close energies. In this talk I will show our final answer about the ground state--the striped state--which is confirmed by four state-of-the-art numerical methods. We then study the superconductivity in the stripes, and show that the additional terms beyond Hubbard model may be necessary to induce long range superconductivity.