标题： 具有环状交换相互作用的硬核玻色子模型中激子玻色液体相的可能实现 显示英文标题

标题： Possible realization of the Exciton Bose Liquid phase in a hard-core boson model with ring-only exchange interactions

摘要： 我们研究了一个在正方形晶格上仅具有环交换作用的硬核玻色子模型，其中$K_1$项作用于 1$\times$1 个晶胞，而$K_2$项作用于 1$\times$2 和 2$\times$1 个晶胞，其目标是实现由 Paramekanti 等人首次提出的新型激子玻色液体（EBL）相 [Phys. Rev. B{\bf 66}, 054526 (2002)]。我们构建了适用于 EBL 的 Jastrow 类变分波函数，研究了它们的形式性质，然后将其作为投影量子蒙特卡洛研究的种子。 使用格林函数蒙特卡洛方法，我们得到了一个无偏的相图，其中在半填充时显示出小的$K_2$时的电荷密度波，中间的$K_2$时的价键固体，以及可能在大的$K_2$时的EBL相。在非半填充情况下，EBL相存在于中间的$K_2$时，并在低于1/2的密度范围内保持稳定，直到较低密度时发生相分离。 显示英文摘要

摘要： We investigate a hard-core boson model with ring-only exchanges on a square lattice, where a $K_1$ term acts on 1$\times$1 plaquettes and a $K_2$ term acts on 1$\times$2 and 2$\times$1 plaquettes, with a goal of realizing a novel Exciton Bose Liquid (EBL) phase first proposed by Paramekanti, et al [Phys. Rev. B {\bf 66}, 054526 (2002)]. We construct Jastrow-type variational wave functions for the EBL, study their formal properties, and then use them as seeds for a projective Quantum Monte Carlo study. Using Green's Function Monte Carlo, we obtain an unbiased phase diagram which at half-filling reveals CDW for small $K_2$, valence bond solid for intermediate $K_2$, and possibly for large $K_2$ the EBL phase. Away from half-filling, the EBL phase is present for intermediate $K_2$ and remains stable for a range of densities below 1/2 before phase separation occurs at lower densities.