Hubbard模型中格林函数的数值计算

摘要

From the Hubbard model, we calculated the Green's function of the system with the dynamical mean-field theory and the quantum Monte Carlo simulation. We also had a thorough discussion on the numerical results of the Green's function in paramagnetic and antiferromagnetic orders and gave the variations of Green's function at different temperatures and different Hubbard energies. From the analysis of these results, we concluded that with the decrease of the temperature or the increase of the Hubbard energy, the system would have Mott transition from metal to insulator.%从Hubbard模型出发,由动态平均场论方法结合量子蒙特卡洛模拟数值求解系统的格林函数,重点讨论在顺磁序和反磁序情形下格林函数的数值结果,给出在不同温度和不同Hubbard能下格林函数的变化情形,从格林函数的变化可以分析得到在温度降低或Hubbard能升高时,系统会发生从金属到绝缘体的Mott转变.