发表机构
School of Physics, Peking University; Institute for Advanced Study in Physics, Zhejiang University（北京大学物理学院; 浙江大学物理高等研究中心）
机构由 AI 辅助整理，请以论文原文为准。AI 中文总结
运用非微扰多体自旋GW方法和协方差方法研究超导体哈伯德模型，计算单粒子格林函数和两体相关函数，关键转变温度与实验数据定量相符，展示费米面演变，为研究强关联系统提供新途径。
AI 中文摘要
我们采用非微扰多体自旋GW方法来计算单粒子格林函数，并运用协方差方法评估超导体哈伯德模型的两体相关函数。发现关键转变温度，即尼尔温度和超导临界温度Tc与实验数据在定量上一致。还展示了不同掺杂区域费米面的演变，清楚地显示了从赝能隙到奇异金属再到费米液相的转变。该方法已在强耦合和低温下进行了基准测试，且不存在费米子符号问题。对高达64×64晶格的模拟也是可行的，从而有可能接近热力学极限。这种方法可能为研究强关联系统，特别是铜酸盐超导体提供一条新途径。
英文摘要
We employ the nonperturbative many-body spin GW method to compute the single-particle Green's function, and the covariance method to evaluate the two-body correlation functions, for the Hubbard model of superconductors. The method, benchmarked at strong coupling and low temperatures, allows simulations on lattices up to $64\times64$, thereby enabling access to the thermodynamic limit. We find the key transition temperatures---namely the Néel temperature and the superconducting critical temperature $T_c$---to be in quantitative agreement with experimental data. Above the $d$-wave superconducting dome, there exists a broad pseudogap region in which the normal-state excitations are suppressed. These results indicate our approach may offer a new route toward investigating strongly correlated systems, especially cuprate superconductors.
Comments19 pages, 8 figures
