论文标题
对称性扰动理论与反铁磁相中的大阶
Symmetry-broken perturbation theory to large orders in antiferromagnetic phases
论文作者
论文摘要
我们引入了连接的确定性算法的自旋对称性破裂扩展[Phys。莱特牧师。 119，045701（2017）]。抗铁磁态周围的系统扰动膨胀允许直接在磁有序的相中进行数值精确的计算。我们在半填充时显示了三维立方哈伯德模型的磁相图和热力学的新精确结果。通过对低至中间耦合方案的顺序参数的详细计算，我们建立了N {é} EL相边界。证明其附近的关键行为与$ O（3）$ Heisenberg通用类兼容。通过通过相变的温度降低熵的演变，我们在$ u/t \！= \！4 $中确定不同的物理状态。我们为抗铁磁圆顶内部深处的几个热力学量提供定量结果，直至较大的相互作用强度，并研究Slater和Heisenberg政权之间的交叉。
We introduce a spin-symmetry-broken extension of the connected determinant algorithm [Phys. Rev. Lett. 119, 045701 (2017)]. The resulting systematic perturbative expansions around an antiferromagnetic state allow for numerically exact calculations directly inside a magnetically ordered phase. We show new precise results for the magnetic phase diagram and thermodynamics of the three-dimensional cubic Hubbard model at half-filling. With detailed computations of the order parameter in the low to intermediate-coupling regime, we establish the N{é}el phase boundary. The critical behavior in its vicinity is shown to be compatible with the $O(3)$ Heisenberg universality class. By determining the evolution of the entropy with decreasing temperature through the phase transition we identify the different physical regimes at $U/t\!=\!4$. We provide quantitative results for several thermodynamic quantities deep inside the antiferromagnetic dome up to large interaction strengths and investigate the crossover between the Slater and Heisenberg regimes.
