论文标题
三维电子气体的低密度相图
Low-density Phase Diagram of the Three-Dimensional Electron Gas
论文作者
论文摘要
使用差异和扩散量子蒙特卡洛方法来研究以非常低的密度的三维均质电子气体的零温度相图。使用Slater-Jastrow-backflow和Slater-Jastrow多体波函数在不同的密度和有限的模拟细胞中的自旋极化下，使用Slater-Jastrow-backflow和Slater-Jastrow多体波函数确定费米流体和以身体为中心的立方体晶体基态能量。使用扭曲平均边界条件以及将每个粒子的能量推断到无限系统大小的热力学极限的能量来消除有限大小的误差。与以前的研究不同，我们的结果表明，电子气体在密度参数$ r_ \ text {s} = 86.6（7）$的情况下直接从顺磁性流体到体为中心的立方晶体进行一阶量子相变，没有稳定区域的稳定区域。但是，可能是从抗铁磁晶体到$ r_ \ text {s} = 93（3）$的磁相过渡到铁磁晶体的。
Variational and diffusion quantum Monte Carlo methods are employed to investigate the zero-temperature phase diagram of the three-dimensional homogeneous electron gas at very low density. Fermi fluid and body-centered cubic Wigner crystal ground state energies are determined using Slater-Jastrow-backflow and Slater-Jastrow many-body wave functions at different densities and spin polarizations in finite simulation cells. Finite-size errors are removed using twist-averaged boundary conditions and extrapolation of the energy per particle to the thermodynamic limit of infinite system size. Unlike previous studies, our results show that the electron gas undergoes a first-order quantum phase transition directly from a paramagnetic fluid to a body-centered cubic crystal at density parameter $r_\text{s} = 86.6(7)$, with no region of stability for an itinerant ferromagnetic fluid. However there is a possible magnetic phase transition from an antiferromagnetic crystal to a ferromagnetic crystal at $r_\text{s}=93(3)$.
