三腿梯子上硬核玻色-哈伯德模型的量子蒙特卡罗研究  

Quantum Monte-Carlo Simulation of the Hard-core Bose-Hubbard Model on the Three-leg Ladder

作　　者：冯乐[1] 张万舟[1] Feng Le Zhang Wanzhou(School of Physics and Optoelectronics, Taiyuan University of Technology, Taiyuan 030024, Chin)

机构地区：[1]太原理工大学物理与光电工程学院,太原030024

出　　处：《河南师范大学学报（自然科学版）》2017年第2期23-28,共6页Journal of Henan Normal University(Natural Science Edition)

基　　金：国家自然科学基金(11305113)

摘　　要：运用集团平均场和密度矩阵重整化群方法得到三腿梯子中玻色-哈伯德模型基于z方向密度交错排布的超固体相,比单层三角晶格多一种超固体.然而平均场超流序参量没有考虑超流的方向,这种超固体的本质有待于进一步探索.本文运用可靠的有向圈随机序列展开量子蒙特卡罗方法模拟了三腿梯子上硬核玻色-哈伯德模型,通过测量层内和层间的结构因子和超流刚硬度,发现系统具有密度ρ=1/2的固体,增加量子隧穿后,z方向不存在超固体.计算结果有助于冷原子实验寻找新的量子相.By combination of the cluster mean-filed and density matrix renormalization methods, the hard-core Bose- Hubbard model on the three-leg ladder was studied and found the supersolid phase based on the density wave phase along the 2： direction, an additional supersolid phase compared with the hard-core bosons on the one-layered triangular lattices. However, the superfluid order denoted by the mean-field theory did not consider the direction, the nature of the supersolid needs further exploration. In this paper,with the stochastic series expansion directed loop quantum Monte Carlo method, we simulated the hard-core Bose-Hubbard model on the three-leg ladder. By measuring the structured factors and the superfluid stiffness, we found that the system has the solid with density 1/2 while the supersolid along the 2： direction does not exist with nonzero quan-tum tunneling. The calculated results are helpful to guide cold atoms experiment to find new quantum phases.

关 键 词：量子蒙特卡罗方法 超固体 三腿梯子 玻色-哈伯德模型 

分 类 号：O413[理学—理论物理]