Phase diagram of interacting bosons on the honeycomb lattice
Phase diagram of interacting bosons on the honeycomb lattice
复制标题
DOI：
10.1103/physrevb.75.174301
复制
发表时间：
2007-01
影响因子：
3.7
通讯作者：
S. Wessel
中科院分区：
文献类型：
--
作者：
S. Wessel
我们用大规模的量子蒙特卡罗模拟研究了蜂窝晶格上排斥相互作用玻色子的基态性质。在硬核极限下，半填充系统发展出足够强的近邻排斥的长程对角有序。这种交错的固体在一级量子相变时熔化成超流体相，没有任何中间超固体相的存在。在超流相内，超流体密度和可压缩性均在四分之一的颗粒(空穴)密度附近出现局部极小值，而密度和凝析分数在该区域出现拐点。放松了硬核约束，软核玻色子出现了超固态相。超流体密度的抑制被发现在足够大的、有限的现场斥力下持续存在。
We study the ground-state properties of repulsively interacting bosons on the honeycomb lattice using large-scale quantum Monte Carlo simulations. In the hard-core limit, the half-filled system develops long-ranged diagonal order for sufficiently strong nearest-neighbor repulsion. This staggered solid melts at a first-order quantum phase transition into the superfluid phase, without the presence of any intermediate supersolid phase. Within the superfluid phase, both the superfluid density and the compressibility exhibit local minima near the particle (hole) density of one quarter, while the density and the condensate fraction show inflection points in this region. Relaxing the hard-core constraint, supersolid phases emerge for soft-core bosons. The suppression of the superfluid density is found to persist for sufficiently large, finite on-site repulsion.