Charge-Density-Wave to Spin-Density-Wave Transition in the Extended Hubbard Model

Monte Carlo simulations are used to study the charge-density-wave to spin-density-wave transition in the one-dimensional Hubbard model with on-site ($U$) and nearest-neighbor ($V$) repulsion. The transition is found to be continuous for small $U$ and first order for large $U$, with the crossover occurring around $U\sim 3$. The transition line deviates somewhat from the theoretical prediction $U=2V$ towards the charge-density-wave phase for intermediate coupling. A qualitative explanation for the results is given by use of strong-coupling arguments.