标题： 使用B-DMFT计算玻色-哈伯德模型的谱函数的数值计算 显示英文标题

标题： Numerical calculation of spectral functions of the Bose-Hubbard model using B-DMFT

摘要： 我们计算了在三维简单立方晶格上，通过玻色子动态平均场理论（B-DMFT）得到的玻色-哈伯德模型的动量依赖谱函数。 使用连续时间量子蒙特卡洛方法结合最大熵方法来求解自洽的B-DMFT方程，并进行实频的解析延拓。 给出了弱、中等和强相互作用的结果。 在弱相互作用和强相互作用极限下，与微扰理论得到的结果有很好的一致性。 相比之下，在中等相互作用下，结果存在显著差异，表明在此区域微扰方法无法描述相互作用玻色子的动力学。 显示英文摘要

摘要： We calculate the momentum dependent spectral function of the Bose-Hubbard model on a simple cubic lattice in three dimensions within the bosonic dynamical mean-field theory (B-DMFT). The continuous-time quantum Monte Carlo method is used to solve the self-consistent B-DMFT equations together with the maximum entropy method for the analytic continuation to real frequencies. Results for weak, intermediate, and strong interactions are presented. In the limit of weak and strong interactions very good agreement with results obtained by perturbation theory is found. By contrast, at intermediate interactions the results differ significantly, indicating that in this regime perturbative methods fail do describe the dynamics of interacting bosons.